[Request] netstandard2 version of the package

[ig-sinicyn]

There is a warning when referencing the NCuid package from a net core project:

NU1701	Package 'NCuid 1.0.0' was restored using 
'.NETFramework,Version=v4.6.1, .NETFramework,Version=v4.6.2, .NETFramework,Version=v4.7, .NETFramework,Version=v4.7.1, .NETFramework,Version=v4.7.2, .NETFramework,Version=v4.8' 
instead of the project target framework '.NETCoreApp,Version=v3.1'.
This package may not be fully compatible with your project.

A new version with netstandard support will be pretty welcome:)