Update README

README.md

@@ -5,6 +5,14 @@ server used for WEnotes. Its main purpose is to allow WEnotes
 clients to subscribe to topics (channels, tags, rooms) of
 interest.
 
+It also serves as a simple proxy to the backing CouchDB server
+so that all requests can happen on port 80 (avoiding problems with
+networks that filter other ports).
+
+And its simple webserver provides an incoming endpoint for
+integrations with [Rocket.Chat](https://rocket.chat) (or
+presumably Slack or Mattermost, but those are untested).
+
 `server.js` is intended to be run under a supervisor such as
 [forever](https://www.npmjs.com/package/forever) or
 [pm2](http://pm2.keymetrics.io/).