Be explicit about working in public
Point to security file from contributors page
Note that twitter is my preferred contact method
Extricate public info from "where work happens"

We don't "do work" on Twitter, Facebook, or Tumblr. Those are ways we
communicate with the general public, but not ways we communicate with
each other as work.
Tweak about page per @ceboudreaux

Aligned contact us right (?!), changed call to action under get
involved (clicking the link doesn't make you a contributor).