File handling: App data locations

Xamarin.Forms has this doc on file handling - https://learn.microsoft.com/en-gb/xamarin/xamarin-forms/data-cloud/data/files?tabs=windows

It's not going to be fully useful for .NET MAUI. There's not anything particularly useful there. However, what would be useful is content on where all the Environment.SpecialFolder properties map to on each platform, and recommendations of where apps should store their data. Users have already requested this.