CSS: Add `margin-right` to `.bio`

Otherwise the bio will be touching the grey line to it's right, which is
not aesthetically pleasing.

Before:
![screen shot 2013-06-20 at 00 38 14](https://f.cloud.github.com/assets/730342/678295/dfe5a222-d930-11e2-91dd-0f53dbb7dcc3.png)

After:
![screen shot 2013-06-20 at 00 37 24](https://f.cloud.github.com/assets/730342/678297/eb61a36c-d930-11e2-9de2-35433f01130d.png)