How to run this app?

[rajeshwarpatlolla]

I have cloned this repository and tried running with ionic serve. But i am getting this error.

Your config.xml file does not have a <content> element. 
Add something like: <content src="index.html"/> (CLI v1.3.22)

Your system information:

OS: Distributor ID: Ubuntu Description: Ubuntu 14.04.2 LTS 
Node Version: v0.10.33
Cordova CLI: 4.3.0
Ionic CLI Version: 1.3.22

Please let me know how to run this app?