.NET Core / 5.0+ port

[Nickelony]

Another hard choice, especially because the current .NET Framework 4 version doesn't require any additional runtimes installed when running from freshly installed Windows 7 images and above.
Let's not forget that .NET Framework 4 also works on WinXP... if anyone's still into that.
Just like #4 I don't really see a reason why I'd want to port this onto .NET Core / 5.0+, especially because there are no real benefits of doing so.