title: Pdf.js add thumbnail view
body: <p>I was able to display the pdf pages and navigate through them. The <a href="https://github.com/mozilla/pdf.js/tree/master/examples/helloworld" rel="nofollow noreferrer">helloworld</a> example guided me.</p>
  
  <p>But now I am struggling to add a thumbnails view. Is there a function or a class that I should extend to generate the view. Or is the only way to create a thumbnails view is by looping through the pdf pages and creating images for each.</p>