Update README.md (#876)

Author: ardalis

README.md

@@ -55,20 +55,14 @@ By default the site uses HTTPS and expects you to have a self-signed developer c
   - [Related Projects](#related-projects)
 
 ## Give a Star! :star:
+
 If you like or are using this project to learn or start your solution, please give it a star. Thanks!
 
 Or if you're feeling really generous, we now support GitHub sponsorships - see the button above.
 
 ## Versions
 
-The main branch is now using .NET 8. If you need a previous version use one of these tagged commits:
-
-- [7.0](https://github.com/ardalis/CleanArchitecture/releases/tag/v8)
-- [6.0](https://github.com/ardalis/CleanArchitecture/releases/tag/dotnet-6)
-- [5.0](https://github.com/ardalis/CleanArchitecture/releases/tag/dotnet-core-5)
-- [3.1](https://github.com/ardalis/CleanArchitecture/tree/dotnet-core-3.1)
-- [2.2](https://github.com/ardalis/CleanArchitecture/tree/dotnet-core-2.2)
-- [2.0](https://github.com/ardalis/CleanArchitecture/tree/dotnet-core-2.0)
+The main branch is now using **.NET 9**. This corresponds with NuGet package version 10.x. Previous versions are available - see our [Releases](https://github.com/ardalis/CleanArchitecture/releases).
 
 ## Learn More
 
@@ -91,6 +85,34 @@ First, install the template from [NuGet (https://www.nuget.org/packages/Ardalis.
 dotnet new install Ardalis.CleanArchitecture.Template
 ```
 
+You can see available options by running the command with the `-?` option:
+
+```powershell
+dotnet new clean-arch -?
+ASP.NET Clean Architecture Solution (C#)
+Author: Steve Smith @ardalis, Erik Dahl
+
+Usage:
+  dotnet new clean-arch [options] [template options]
+
+Options:
+  -n, --name <name>       The name for the output being created. If no name is specified, the name of the output
+                          directory is used.
+  -o, --output <output>   Location to place the generated output.
+  --dry-run               Displays a summary of what would happen if the given command line were run if it would result
+                          in a template creation.
+  --force                 Forces content to be generated even if it would change existing files.
+  --no-update-check       Disables checking for the template package updates when instantiating a template.
+  --project <project>     The project that should be used for context evaluation.
+  -lang, --language <C#>  Specifies the template language to instantiate.
+  --type <project>        Specifies the template type to instantiate.
+
+Template options:
+  -as, --aspire  Include .NET Aspire.
+                 Type: bool
+                 Default: false
+```
+
 You should see the template in the list of templates from `dotnet new list` after this installs successfully. Look for "ASP.NET Clean Architecture Solution" with Short Name of "clean-arch".
 
 Navigate to the parent directory in which you'd like the solution's folder to be created.
@@ -198,30 +220,32 @@ If you're used to building applications as single-project or as a set of project
 
 Steve Smith also maintains Microsoft's reference application, eShopOnWeb, and its associated free eBook. Check them out here:
 
-- [eShopOnWeb on GitHub](https://github.com/dotnet-architecture/eShopOnWeb)
+- [eShopOnWeb on GitHub](https://github.com/nimblepros/eShopOnWeb) (now supported by [NimblePros](https://nimblepros.com)
 - [Architecting Modern Web Applications with ASP.NET Core and Microsoft Azure](https://aka.ms/webappebook) (eBook)
 
-Note that the goal of this project and repository is **not** to provide a sample or reference application. It's meant to just be a template, but with enough pieces in place to show you where things belong as you set up your actual solution. Instead of useless "Class1.cs" there are a few real classes in place. Delete them as soon as you understand why they're there and where you should put your own, similar files.
+Note that the goal of this project and repository is **not** to provide a sample or reference application. It's meant to just be a template, but with enough pieces in place to show you where things belong as you set up your actual solution. Instead of useless "Class1.cs" there are a few real classes in place. Delete them as soon as you understand why they're there and where you should put your own, similar files. There *is* a sample application in the `/sample` folder, if you're looking for that.
 
 ## History and Shameless Plug Section
 
-I've used this starter kit to teach the basics of ASP.NET Core using Domain-Driven Design concepts and patterns for some time now (starting when ASP.NET Core was still in pre-release). Typically I teach a one- or two-day hands-on workshop ahead of events like DevIntersection, or private on-site workshops for companies looking to bring their teams up to speed with the latest development technologies and techniques. Feel free to [contact me](https://ardalis.com/contact-us) if you'd like information about upcoming workshops.
+I've used this starter kit to teach the basics of ASP.NET Core using Domain-Driven Design concepts and patterns for some time now (starting when ASP.NET Core was still in pre-release). Typically I teach a one- or two-day hands-on workshop ahead of events like DevIntersection, or private on-site workshops for companies looking to bring their teams up to speed with the latest development technologies and techniques. Feel free to [contact me](https://nimblepros.com/) if you'd like information about upcoming workshops.
 
 # Design Decisions and Dependencies
 
-The goal of this sample is to provide a fairly bare-bones starter kit for new projects. It does not include every possible framework, tool, or feature that a particular enterprise application might benefit from. Its choices of technology for things like data access are rooted in what is the most common, accessible technology for most business software developers using Microsoft's technology stack. It doesn't (currently) include extensive support for things like logging, monitoring, or analytics, though these can all be added easily. Below is a list of the technology dependencies it includes, and why they were chosen. Most of these can easily be swapped out for your technology of choice, since the nature of this architecture is to support modularity and encapsulation.
+The goal of this solution template is to provide a fairly bare-bones starter kit for new projects. It does not include every possible framework, tool, or feature that a particular enterprise application might benefit from. Its choices of technology for things like data access are rooted in what is the most common, accessible technology for most business software developers using Microsoft's technology stack. It doesn't (currently) include extensive support for things like logging, monitoring, or analytics, though these can all be added easily. Below is a list of the technology dependencies it includes, and why they were chosen. Most of these can easily be swapped out for your technology of choice, since the nature of this architecture is to support modularity and encapsulation.
 
 ## Where To Validate
 
 Validation of user input is a requirement of all software applications. The question is, where does it make sense to implement it in a concise and elegant manner? This solution template includes 4 separate projects, each of which might be responsible for performing validation as well as enforcing business invariants (which, given validation should already have occurred, are usually modeled as exceptions).
 
+- [When to Validate and When to Throw Exceptions](https://www.youtube.com/watch?v=dpPcnAT7n7M)
+
 The domain model itself should generally rely on object-oriented design to ensure it is always in a consistent state. It leverages encapsulation and limits public state mutation access to achieve this, and it assumes that any arguments passed to it have already been validated, so null or other improper values yield exceptions, not validation results, in most cases.
 
-The use cases / application project includes the set of all commands and queries the system supports. It's frequently responsible for validating its own command and query objects.
+The use cases / application project includes the set of all commands and queries the system supports. It's frequently responsible for validating its own command and query objects. This is most easily done using a [chain of responsibility pattern](https://deviq.com/design-patterns/chain-of-responsibility-pattern) via MediatR behaviors or some other pipeline.
 
 The Web project includes all API endpoints, which include their own request and response types, following the [REPR pattern](https://deviq.com/design-patterns/repr-design-pattern). The FastEndpoints library includes built-in support for validation using FluentValidation on the request types. This is a natural place to perform input validation as well.
 
-Having validation occur both within the API endpoints and then again at the use case level is redundant, so in this template the choice has been made to validate at the edge of the application, in the API endpoints. This means some future consumer of the Use Cases project will also need to be responsible for its own validation as well, but in the vast majority of cases there won't be any other consumers of the use cases outside of the API endpoints.
+Having validation occur both within the API endpoints and then again at the use case level may be considered redundant. There are tradeoffs to adding essentially the same validation in two places, one for API requests and another for messages sent to Use Case handlers. Following defensive coding, it often makes sense to add validation in both places, as the overhead is minimal and the peace of mind of mind and greater application robustness is often worth it.
 
 ## The Core Project
 
@@ -237,21 +261,24 @@ The Core project is the center of the Clean Architecture design, and all other p
 - Interfaces
 - DTOs (sometimes)
 
+You can learn more about these patterns and how to apply them here:
+
+- [DDD Fundamentals](https://www.pluralsight.com/courses/fundamentals-domain-driven-design)
+- [DDD Concepts](https://deviq.com/domain-driven-design/ddd-overview)
+
 ## The Use Cases Project
 
 An optional project, I've included it because many folks were demanding it and it's easier to remove than to add later. This is also often referred to as the *Application* or *Application Services* layer. The Use Cases project is organized following CQRS into Commands and Queries. Commands mutate the domain model and thus should always use Repository abstractions for their data access. Queries are readonly, and thus do not need to use the repository pattern, but instead can use whatever query service or approach is most convenient. However, since the Use Cases project is set up to depend on Core and not directly on Infrastructure, there will still need to be abstractions defined for its data access. And it *can* use things like specifications, which can sometimes help encapsulate query logic as well as result type mapping. But it doesn't *have* to use repository/specification - it can just issue a SQL query or call a stored procedure if that's the most efficient way to get the data.
 
-Although this is an optional project to include (without it, your API endpoints would just work directly with the domain model or query services), it does provide a nice UI-ignorant place to add automated tests.
+Although this is an optional project to include (without it, your API endpoints would just work directly with the domain model or query services), it does provide a nice UI-ignorant place to add automated tests, and lends itself toward applying policies for cross-cutting concerns using a Chain of Responsibility pattern around the message handlers (for things like validation, caching, auth, logging, timing, etc.).
 
 ## The Infrastructure Project
 
-Most of your application's dependencies on external resources should be implemented in classes defined in the Infrastructure project. These classes should implement interfaces defined in Core. If you have a very large project with many dependencies, it may make sense to have multiple Infrastructure projects (e.g. Infrastructure.Data), but for most projects one Infrastructure project with folders works fine. The sample includes data access and domain event implementations, but you would also add things like email providers, file access, web api clients, etc. to this project so they're not adding coupling to your Core or UI projects.
-
-The Infrastructure project depends on `Microsoft.EntityFrameworkCore.SqlServer` and `Autofac`. The former is used because it's built into the default ASP.NET Core templates and is the least common denominator of data access. If desired, it can easily be replaced with a lighter-weight ORM like Dapper. Autofac (formerly StructureMap) is used to allow wireup of dependencies to take place closest to where the implementations reside. In this case, an InfrastructureRegistry class can be used in the Infrastructure class to allow wireup of dependencies there, without the entry point of the application even having to have a reference to the project or its types. [Learn more about this technique](https://ardalis.com/avoid-referencing-infrastructure-in-visual-studio-solutions). The current implementation doesn't include this behavior - it's something I typically cover and have students add themselves in my workshops.
+Most of your application's dependencies on external resources should be implemented in classes defined in the Infrastructure project. These classes should implement interfaces defined in Core. If you have a very large project with many dependencies, it may make sense to have multiple Infrastructure projects (e.g. Infrastructure.Data), but for most projects one Infrastructure project with folders works fine. The template includes data access and domain event implementations, but you would also add things like email providers, file access, web api clients, etc. to this project so they're not adding coupling to your Core or UI projects.
 
 ## The Web Project
 
-The entry point of the application is the ASP.NET Core web project. This is actually a console application, with a `public static void Main` method in `Program.cs`. It currently uses the default MVC organization (Controllers and Views folders) as well as most of the default ASP.NET Core project template code. This includes its configuration system, which uses the default `appsettings.json` file plus environment variables, and is configured in `Startup.cs`. The project delegates to the `Infrastructure` project to wire up its services using Autofac.
+The entry point of the application is the ASP.NET Core web project (or possibly the AspireHost project, which in turn loads the Web project). This is actually a console application, with a `public static void Main` method in `Program.cs`. It leverages FastEndpoints and the REPR pattern to organize its API endpoints.
 
 ## The SharedKernel Project