title: Markdown Incorrectly Underlining Header
body: <p>We are using the RoadKill Wiki with Markdown as the syntax.  When I create a header using <code>###Header 3###</code> I get a header with the correct text size/formatting but I also am getting a separator which spans the entire page width.</p>
  
  <p>According to the documentation <a href="https://github.com/adam-p/markdown-here/wiki/Markdown-Cheatsheet" rel="nofollow">here</a>, only the first and second level headers should have an underline.</p>
  
  <p>Is there something setup incorrectly that is making the headers 3, 4, etc. display with a separator and can this be changed in a style sheet or something.</p>