title: Break Google Apps HTMLService Page into multiple .html files
body: <p>I want to combine a few related HTMLService interface in to a tabbed page.  I can get the tabs working <a href="https://stackoverflow.com/a/18581972/3354226">using the code here</a>.  But I want to put the page for each Tab into a different html file in the project. How would I show Billets.html inside the div below?  Basically replacing "Put the Billet Locations here" with the contents of the html file.  My goal is to have a Main.html file that is loaded and shows Tabs for various tasks, using different files for the contents of each Tab to better organize the Project.  Iam also looking to have each item load in the most efficient manor, meaning either loaded when the tab is selected (it may never be selected by a given user) or loading it all at the onset.</p>
  
  <pre><code>&lt;div id="tabs-2"&gt;
    &lt;p&gt;Put the Billet Locations App here&lt;/p&gt;
  &lt;/div&gt;
  </code></pre>