dotnet/maui — reverse-engineered prompt

Build me a .NET multi platform app UI framework that lets developers create native apps for Android, iPhone, iPad, Mac, and Windows from one shared C# codebase. I want it to support XAML for building screens, common app UI pieces, navigation, styling, resources, and a way to make each platform feel native while sharing most of the code.

Include starter templates so someone can create a new app quickly from the command line, plus a sample app that proves the same project can run on mobile, tablet, and desktop. Please also add clear setup docs, build scripts, tests, licensing, and contributor guidance so it feels like a serious open source framework.

Keep the first version focused on the core developer experience, building an app once and running it across devices. Look up current .NET docs online if you need to.