Add a page on the wiki & a table about all of the places chat is available and bridged

Right now it's only briefly mentioned on the wiki landing page--we need to make a simple page (or adjust the landing page) to mention everywhere chat is available/bridged.

We will need to add Matrix once it's setup as well.

@bennyvasquez, do you think this should be a separate page or should we just add it to the landing page?