Add troubleshooting suggesting to WebAssembly documention

[MikeyWetzel]

Regarding this page: https://docs.avaloniaui.net/docs/guides/platforms/how-to-use-web-assembly

Please consider adding support for Visual Studio 2022, explaining that "dotnet workload install wasm-tools" installs the wasm tools only for command line builds. For Visual Studio 2022, users need to make sure the ".NET 9.0 WebAssembly Build Tools" are added via the Visual Studio Installer, under Individual Components.

Then, regarding this text at the bottom: "If you have not performed the step to install required workloads, you might encounter errors when running the app in your browser later (e.g. System.DllNotFoundException: libSkiaSharp) and you will need to rebuild again before the app will run."

Please consider adding a line: If you are launching a browser project from Visual Studio, and the app does not get past the Avalonia splash screen, you can use Chrome DevTools (F12) and view Console output. If you see errors including System.DllNotFoundException: libSkiaSharp, this indicates that the WebAssembly tools were not properly added through the Visual Studio Installer.

This simple troubleshooting would've saved hours of my life. :) I'm just hoping to spare the next person to hit this problem. Not having the wasm build tools added to Visual Studio can be incredibly difficult scenario to figure out. (For the vast majority of us who aren't wasm experts, but just want a project to work in a browser.)