Make the copyright license clear for torspec and proposals
Once upon a time, the tor spec files and proposals were in the Tor tarball, so they clearly were covered under Tor's copyright license (3-clause BSD).
But now they're in their own git repository.
I think maybe they technically have no copyright license now?
We should pick one (I vote cc-by) and try to apply it. This plan could become tricky for proposals, because there are a lot of authors on proposals by now.