Fix retina images in HTML markup

Fixes any

-`<img class="the-graph" src="http://static.domain.com/images/graph-@2x.gif" />`
-`<img class="the-graph" src="//static.domain.com/images/graph-@2x.gif" />`
Remove closing `?>` at the end of file

Ommiting closing tag at the end of file eliminates the possibility for unwanted whitespace in the output.