v0.5-alpha is released

Half of the work is done! The feature and the codebase will be stable. There will be no big changes any more, only bug fixing and more platform support.
ROADMAP:

• v0.5: publish the NuGet version
• v0.6: WPF/.NET 5 support
• v0.7: UWP support
• v0.8: WinUI support
• v0.9: Avalonia support