Update README change to mention npx mongosh.

Author: FGasper

README.md

@@ -22,7 +22,9 @@ Once downloaded, you will have to extract the binary and add it to your PATH
 variable. For detailed instructions for each of our supported platforms, please visit
 [installation documentation](https://www.mongodb.com/docs/mongodb-shell/install#mdb-shell-install).
 
-You can also run `download_latest.sh` to download a `mongosh` binary. You can use
+Alternatively:
+- Run `npx mongosh` to run mongosh without a full installation.
+- Run `download_latest.sh` to download a `mongosh` binary. You can use
 this script without cloning the repository thus:
 ```
 curl -fsSL https://raw.githubusercontent.com/mongodb-js/mongosh/refs/heads/main/download_latest.sh | sh