add video and mailing list links to readme

Author: jamesmacaulay

README.md

@@ -6,6 +6,10 @@
 
 [Elm](http://elm-lang.org/)-style FRP for Clojure and ClojureScript.
 
+Here's a [conference talk with some demos](https://www.youtube.com/watch?v=rOKOCAkHNYw)!
+
+Here's a [mailing list on Google Groups](https://groups.google.com/d/forum/zelkova-frp)!
+
 ## Bullet points
 
 * signal graphs are static, just like in Elm ([why?](https://www.youtube.com/watch?v=Agu6jipKfYw))