title: jQuery not working in chrome extension popup
body: <p>I'm building my first chrome extension, and I'm having some trouble. I want to use jQuery on popup.html. The popup otherwise works fine, but the jQuery doesn't work. </p>
  
  <p><strong>Edit:</strong> I changed it, here's the new code, which still doesn't work. Any ideas? I've spent over two hours trying to figure it out. I'm a beginner to extensions and quite rusty in javascript and jquery, so it could definitely be something small and embarrassing... Thanks so much!</p>
  
  <p><strong>manifest.json</strong></p>
  
  <pre><code>  "content_scripts": [{
      "matches": [website], 
      "js": [
      "content.js", 
      "https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"]
     }], 
  </code></pre>
  
  <p><strong>popup.html</strong></p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html&gt;
  &lt;head&gt;
      &lt;title&gt;First Google Extension&lt;/title&gt;
      &lt;style&gt;
      body { 
          font-family: "Segoe UI"; 
          width: 300px; 
          font-size: 14px; 
          }; 
  
      #changeMe {
          color: blue; 
          font-style: bold; 
          }; 
      &lt;/style&gt;
  
  &lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"&gt;&lt;/script&gt;
  &lt;/head&gt;
  
  &lt;body&gt;
      Welcome to my first Google Chrome Extension! &lt;br&gt; 
      &lt;div id="changeMe"&gt;
          I'm different!
      &lt;/div&gt;
  &lt;/body&gt;
  
  &lt;/html&gt;
  </code></pre>
  
  <p><strong>popup.js</strong></p>
  
  <pre><code>$(document).ready(function() {
          $("#changeMe").append("Test!");  
  });
  </code></pre>