title: Adding custom buttons
body: <p>Can you add a custom button to extend the functionality of the uploader.
  what I need is the ability to allow the user to enter text into a form after an image has been uploaded.</p>
  
  <p>Is there any documentation on this?
  the goal is to add an additional button that can get the image UUID and open an text area to enter text to post back to the servers.
  thank you.</p>