title: JSPDF .output Image + txt
body: <p>So i have a jspdf script im working with.
  .save works as expected and outputs the image + text elements.</p>
  
  <p>How ever</p>
  
  <p><strong>doc.output() = only text</strong></p>
  
  <p><strong>doc.output('datauristring') = corrupted pdf</strong></p>
  
  <p>I think im missing something
  here is an example of my code</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var imgData = 'data:image/jpeg;base64,/9j/4AAQSkZJRgABAQIAdgB2AAD/examplestringonly...';
  var doc = new jsPDF('p', 'pt');
  doc.text(35, 340, "data notes");
  doc.addImage(imgData, 'JPEG', 350, 40, 200, 40);
  doc.output('datauristring'); </code></pre>
  </div>
  </div>
  </p>