Adds an editor button that puts in an empty paragraph which won't get deleted when you save.
This is a very simple plugin for the default (TinyMCE) editor. It adds
a button that puts in a paragraph which won’t get deleted by the
linebreak-eater (the one that starts munching when you press
“Publish”).
Because sometimes people write poetry and don’t care what typographers
think, and entering HTML code will just disrupt the flow.