title: firefox sdk append html file
body: <p>I append html to a tab of firefox from my script with the following code:</p>
  <p><code>main.js</code>:</p>
  <pre><code>let worker = tabs.activeTab.attach({
      contentScriptFile: [
        data.url(&quot;jquery.min.js&quot;),
        data.url(&quot;worker.js&quot;)
      ],
      contentScriptOptions: contentOptions
    });
    attach(style, tabs.activeTab);
  </code></pre>
  <p><code>worker.js</code>:</p>
  <pre><code>$('body').append(&quot;&lt;div&gt;foo&lt;/div&gt;&quot;);
  </code></pre>
  <p>My question is:
  Is it posible to have the html code to an html file and append the file. This will make the code more beatiful and readable.</p>
  <h1>EDIT:</h1>
  <p>if the previous code submited to mozilla full review, it will be rejected, because creates DOM nodes from HTML strings containing potentially unsanitized data.</p>