Cover dotnet-serve local testing for Blazor WASM (#37010)

Author: guardrex

aspnetcore/blazor/host-and-deploy/webassembly/index.md

@@ -35,6 +35,13 @@ The following deployment strategies are supported:
 
 :::moniker-end
 
+## Serve a Blazor WebAssembly app locally for testing
+
+Many open-source and commercial HTTP servers can serve a published Blazor WebAssembly app locally. For a simple command-line HTTP server, consider using the [`natemcmaster/dotnet-serve` .NET tool](https://github.com/natemcmaster/dotnet-serve).
+
+> [!WARNING]
+> The [`natemcmaster/dotnet-serve` .NET tool](https://github.com/natemcmaster/dotnet-serve) isn't owned or maintained by Microsoft and isn't covered by any Microsoft support agreement or license. Use caution when using a third-party tool, especially for testing security scenarios. Confirm that the tool follows official specifications and adopts security best practices. Keep the tool's version current to obtain the latest bug fixes.
+
 ## Subdomain and IIS sub-application hosting
 
 Subdomain hosting doesn't require special configuration of the app. You ***don't*** need to configure the app base path (the `<base>` tag in `wwwroot/index.html`) to host the app at a subdomain.