title: select document root using jquery
body: <p>I can select the body and html parts of the document using</p>
  
  <pre><code>$('body')
  </code></pre>
  
  <p>and</p>
  
  <pre><code>$('html')
  </code></pre>
  
  <p>respectively, but how do I select the document root?</p>