Making the main content as large as the sidebar

https://docs.auth0.com/logout was not long enough so the bottom of the content was overlapping the sidebar.

before
![image](https://f.cloud.github.com/assets/647691/1294690/65f5ab12-308b-11e3-89af-f0342dd07819.png)

After
![image](https://f.cloud.github.com/assets/647691/1294693/799fe9fc-308b-11e3-9615-2c05b8ed98fc.png)