Support distribution via OpenUPM

[laicasaane]

Please make tag releases so the package can be distributed via OpenUPM thus eases the installing/updating process.
https://openupm.com/docs/adding-upm-package.html#package-metadata-yaml-file

[laicasaane]

OpenUPM can also help resolve NuGet dependencies if they are available on this curated list:
https://github.com/xoofx/UnityNuGet/blob/master/registry.json

And you don't have to redistribute .dll such as:
System.ComponentModel.Annotations.dll
System.Runtime.CompilerServices.Unsafe.dll
System.Threading.Channels.dll

The only requirement is these NuGet dependencies must be declared in package.json.
https://openupm.com/nuget/