Harden CSP and open connect src to webmention.io
Harden CSP and open connect src to webmention.io

Default everything to blocked, then open up scripts, styles, and images
to self. Also open scripts to youtube, frames to youtube, and
connections to webmention.

bronzehedwick/chrisdeluca,bronzehedwick/chrisdeluca,bronzehedwick/chrisdeluca,bronzehedwick/chrisdeluca