FYI: RFC7762 established a registry of CSP directives

Hello, folks!

We're moving towards a more modular future for CSP; as opposed to putting
everything into one monolithic doc that advances as a block, we're
splitting things up into various docs that can advance at their own rate.

Thanks to mnot@ and others, https://tools.ietf.org/html/rfc7762 formalizes
this split to some extent, providing a single location (
https://www.iana.org/assignments/content-security-policy-directives/content-security-policy-directives.xhtml#directives)
that
collects all the directives that we (and others!) end up specifying. I'll
be adding super-exciting IANA sections to the various CSP modules we have
lying around, and I hope you'll do the same when you decide that you'd like
to specify your own directive(s).

Thanks!

-mike