These are Project Templates for Visual Studio.
Note: Most plugin development can be done with CodeLab, and it remains the recommend solution. These templates are for people that know they need them.
The templates allow for these six Paint.NET plugin types.
You can install them with this VSIX pack
Unfortunately, these templates use the .NET Framework. The newest Paint.NET alpha (which I wish to target with my plugin, for reasons of having the newest C# 9 features) uses .NET 5. If I do what these templates do (which is target the Paint.NET DLLs, copy plugin dll to FileTypes/Effects folder at post build, then start Paint.NET as the debug action) with the new SDK csproj format as well as targeting `net5.0-windows`, it'll complain of DLL conflicts due to different versions that the plugin is