Add some Restream.io instructions

doc/restream.md

@@ -0,0 +1,9 @@
+# Restream.io
+
+If you're a paid user of [Restream](http://restream.io) you can point it at your Ownstream instance as another place to braodcast to.
+1. Login and go to the "Add Channel" screen.
+<img src="restream1.png">
+1. Select "Custom RTMP"
+<img src="restream2.png">
+1. Add your server information in the format of `rtmp://myserver/live` for the RTMP URL and the Stream Key that matches what is in your `config.yaml` file.
+<img src="restream3.png">