Cleanup unnecessary whitespace and collapse empty tags

[mjszczep]

Another piece of really low-stakes repo tidying... I decided to apply the following two formatting changes (though if anyone disagrees with them stylistically we can talk about it further...)

1. Cleanup whitespace at the end of opening tags--for example, <td >my content</td> becomes <td>my content</td>
2. Collapse empty tags--for example, <td></td> becomes <td />