Reduce content in project description in medium screens

## 768px- width
![screen shot 2014-07-31 at 5 24 29 pm](https://cloud.githubusercontent.com/assets/667753/3770995/c0694eac-18f0-11e4-9086-4e6191d53f98.png)

## 768px width
![screen shot 2014-07-31 at 5 21 13 pm](https://cloud.githubusercontent.com/assets/667753/3770956/5f71b1d4-18f0-11e4-9fcd-bba3f3be76e2.png)

## 999px width
![screen shot 2014-07-31 at 5 21 56 pm](https://cloud.githubusercontent.com/assets/667753/3770957/5f73b8b2-18f0-11e4-97f7-a54235684ac9.png)

## 1000px+ width
![screen shot 2014-07-31 at 5 23 37 pm](https://cloud.githubusercontent.com/assets/667753/3770986/9e93ebf2-18f0-11e4-8783-8a84970db858.png)

Closes #460.

/cc @snconnolly