Add .NET Standard 2.0 package

[cmeeren]

First, thanks for yet another useful library. Seems to work wonderfully, and really simplifies triggering INPC with calculated properties. While my preferred method so far is PropertyChanged.Fody (due to being essentially boilerplate-free), it doesn't work with .NET Standard F# projects (and there are F# edge cases it doesn't tackle that your library seems to handle well), and I need to ship soon, so I decided to give CalculatedProperties a try.

This seems to work fine with .NET Standard 2.0, but my build output is full of the following two warnings:

warning NU1701: Package 'Microsoft.Bcl 1.1.8' was restored using '.NETFramework,Version=v4.6.1' instead of the project target framework '.NETStandard,Version=v2.0'. This package may not be fully compatible with your project.
warning NU1701: Package 'Nito.CalculatedProperties 1.0.0' was restored using '.NETFramework,Version=v4.6.1' instead of the project target framework '.NETStandard,Version=v2.0'. This package may not be fully compatible with your project.

I suppose this could be fixed if there was a .NET Standard 2.0 package for this on NuGet. I realize that you might not support this project any longer, what with it being over 2.5 years since the last commit, but I'd really appreciate it if you could. :)

[StephenCleary]

Actually, this project is still alive. The netstandard version is using a different nuget package id, and has its own GH project.

Eventually, this project will be replaced by that one. Sorry for the confusion!

[cmeeren]

Great, thanks! 👍

[DunetsNM]

cmeeren (sorry for offtop), Fody and other IL rewriters (like PostSharp) have very limited if any support of nested dependencies and dependencies changing at runtime. CalculatedProperties do it with no special effort which is the biggest win IMO.
In my projects dependency chains span through multiple levels across domain and view models and there's zero explicit RaisePropertyChanged invocations in all source code.

[cmeeren]

Thanks @DunetsNM, I appreciate the clarification.

[StephenCleary]

Reopening this as a reminder to myself to add forwarding docs.