README + fixing codeblocks

I've added a README, with some installing instruction.

Also fixed a bug about highlighting a codeblock, it didn't do it properly (see the images below):

**BEFORE**
![before](https://f.cloud.github.com/assets/3680682/1187806/62fa838a-239b-11e3-852c-6dab9f92a936.png)

**AFTER**
![after](https://f.cloud.github.com/assets/3680682/1187807/69aef7ba-239b-11e3-8b39-66d8fac57ace.png)

See?