Add NuGet package and build scripts

pkg/nuget/README.md

@@ -0,0 +1,17 @@
+# NuGet package
+
+Install from [NuGet gallery package]() (recommended):
+
+```powershell
+Install-Package ZeroTier.Sockets
+```
+
+Install from local package
+
+```powershell
+Install-Package ZeroTier.Sockets -Source C:\PathToThePackageDir\
+```
+
+Development notes
+
+ - Microsoft's own documentation on multi-architecture nupkgs was outdated and Marco Siccardi seemed to have [the only correct instructions found anywhere on the internet](https://msicc.net/how-to-create-a-multi-architecture-nuget-package-from-a-uwp-class-library/) to accomplish this.