Propose new RFC for migrating off Sympa.

Heads up @nathenharvey 

I will post to the mailing list (hehe) and hopefully we can get some comments & have this reviewed by the next community meeting.
We've already done a test run of putting the archives on a static site, and it will be _really_ good to get rid of the old machine. I'm in favor of static site, not leaving the sympa machine up.