Suggest that repositories include links to rendered and rfcdiff versions

[chris-wood]

This was brought up on the list. Martin's tooling already sets up READMEs with these links, so we might just add a note documenting what's done.

[martinthomson]

Is this something more appropriate for ietf-gitwg/draft-ietf-git-github-wg-configuration? This is more of a process document than something documenting tools and how things are set up.

[chris-wood]

Yeah, probably. I'll file it over there!