Added some padding to the bottom of the documentation

Added 80px of padding to the bottom of the documentation to give the content some room. 

Before: 
![image](https://cloud.githubusercontent.com/assets/647691/5259182/5b192ac8-79b1-11e4-8825-a4ecc7f3c158.png)

After: 
![image](https://cloud.githubusercontent.com/assets/647691/5259188/69532ce2-79b1-11e4-8b36-fec58771fe5b.png)