title: jquery mobile left menu
body: <p>Throughout the jQuery Mobile docs, they use a left-side menu for navigation that changes to a more mobile friendly version when the browser width is smaller. You can see an example on <a href="http://jquerymobile.com/demos/1.1.1/docs/pages/page-anatomy.html" rel="nofollow">this page.</a></p>
  
  <p>They use this layout throughout the docs, and I can see in the source that they use two divs with the IDs "content-primary" and "content-secondary." My question relates to the fact that I can't find anything about this structure actually discussed in the documentation. It seems very strange that they would not include such a useful widget in the Framework. Did they use custom code to make this, or did I miss it in the documentation somehow?</p>