Description
The AsyncRx.NET project has only ever targeted netstandard2.1. It's not currently clear whether there's any fundamental reason it couldn't target netstandard2.0 (which would enable its use on .NET Framework.)
The obvious issue that occurs with a netstandard2.0 target is that the IAsyncEnumerable<T>, IAsyncEnumerator<T>, and IAsyncDisposable interfaces are missing. However, these are all available in the Microsoft.Bcl.AsyncInterfaces NuGet package.
As an experiment, we should try adding a netstandard2.0 target that uses Microsoft.Bcl.AsyncInterfaces. It's possible this won't work, and that we'll discover some deeper reason why this wasn't done in the first place, in which case we'll either need to revert this change, or work out how we can work around that issue.