title: How can I add custom code to the header
body: <p>How can I add the following line to the header, in a  component?</p>
  
  <pre><code>&lt;!--[if lt IE 9]&gt;&lt;script language="javascript" type="text/javascript" src="js/excanvas.min.js"&gt;&lt;/script&gt;&lt;![endif]--&gt;
  </code></pre>