Accidentally nested rows

Created by: necolas

There is a missing </div> here: https://github.com/twitter/bootstrap/blob/master/docs/index.html#L1085

...and an extra closing </div> here: https://github.com/twitter/bootstrap/blob/master/docs/index.html#L1116

You can see from the code indentation that one row starts too early, leaving it nested within the previous row.