Update readme to markdown style

Changed the `README` to markdown and applied syntax highlighter.

## Before
![Screen Shot 2013-01-18 at 18 39 30](https://f.cloud.github.com/assets/184520/77668/36f1a7ce-6153-11e2-8c71-9988580443cb.png)

## After
![Screen Shot 2013-01-18 at 18 39 14](https://f.cloud.github.com/assets/184520/77669/3b950ba4-6153-11e2-95e5-b0f0aa54922f.png)