Add task kensho link to home page

Ok, Done ! I also did fix some style on mobile.
This is new front page look on desktop 
![screenshot 2014-06-10 00 26 06](https://cloud.githubusercontent.com/assets/1759054/3230170/f23ca358-f09f-11e3-9cea-cc1173889f65.png)
This is on mobile 
![screenshot_2014-06-10-20-01-00](https://cloud.githubusercontent.com/assets/1759054/3230176/fd55ac4e-f09f-11e3-9020-816d4da62d33.png)