title: Add prefix to all images (recursive)
body: <p>I have a folder with more than 5000 images, all with JPG extension.</p>
  
  <p>What i want to do, is to add recursively the "thumb_" prefix to all images.</p>
  
  <p>I found a similar question: <a href="https://stackoverflow.com/questions/4787413/rename-files-and-directories-add-prefix">Rename Files and Directories (Add Prefix)</a>   but i only want to add the prefix to files with the JPG extension.</p>