fix(lang/rust): fill in wkg config

Co-authored-by: Kate Goldenring <[email protected]>

Author: vados-cosmonic

component-model/src/tutorial.md

@@ -137,7 +137,14 @@ Since the calculator world imports the `add` interface, the command component ne
 To do this, we can [`wkg`][wkg] from [`wasm-pkg-tools`][wasm-pkg-tools]. We must first configure wkg to find the `docs:adder` repository:
 
 ```toml
-# TODO required wkg config
+# $XDG_CONFIG_HOME/wasm-pkg/config.toml
+default_registry = "ghcr.io"
+
+[namespace_registries]
+# Tell wkg that packages with the `wasi` namespace are in an OCI registry under ghcr.io/webassembly 
+wasi = { registry = "wasi",  metadata = { preferredProtocol = "oci", "oci" = {registry = "ghcr.io", namespacePrefix = "webassembly/" } } }
+# Tell wkg that the component-book WITs can be found at ghcr.io/bytecodealliance/docs
+docs = { registry = "docs",  metadata = { preferredProtocol = "oci", "oci" = {registry = "ghcr.io", namespacePrefix = "bytecodealliance/" } } }
 ```
 
 > [!NOTE]