Add Demo link to Readme

Author: petercunha

README.md

@@ -2,9 +2,12 @@
 Pad is an extremely lightweight, low-latency, collaborative notepad built with [WebSockets](https://en.wikipedia.org/wiki/WebSocket) and [NodeJS](https://nodejs.org/)!
 
 
-### Run your own server!
+
+## Run your own server!
 ```bash
 git clone https://github.com/petercunha/pad.git
 cd pad
 npm install && npm start
 ```
+
+[Check out our demo](https://paperpad.herokuapp.com/)