Fix readme on usage 

I arrived at your github repo via a link ( https://twitter.com/github/status/450678499813384192 ) but it took a while for me to make sense of how to use this since I'm not a developer (web or otherwise). 

These changes should help people who are in a hurry or who just came by your work by chance.  

Also,
* Some documentation available offline in case user lacks a network connection. 
* A readily accessible basic usage guide for those who accidentally find the code and want to play. Centralized for ease of access and visibility.
* The service website is buried in the github way of showing the description.