Upload bundled package Releases

[bschilder]

Add an optional step at the end of rworkflows action that automatically uploads the bundled package tarball to the appropriate Release.

That said, rworkflows itself is kind of special case, because we also uses Releases to release version of the GitHub Action. Perhaps there's a way to do both in the same repo, but will need to be careful with this so user's can't accidentally call the wrong release tag.

https://github.com/neurogenomics/rworkflows/releases