update to licensing document

I think I posted an earlier link to this document? Since then, however, VCV have changed their rules about taking over abandoned plugins, so I have updated my document to reflect that.

Also, due to sloppiness, I believe the link before was broken. Sorry.

In any case, I think this document is mostly accurate, and will be useful to plugin developers who haven’t thought a lot about licensing (i.e. most of us!).