Add rel=lightbox to all image-links
Add the attribute "rel='lightbox'" to all Links, if the target is an image. `<a href="/path/to/image.jpg">Image</a>` becomes `<a rel="lightbox" href="/path/to/image.jpg">Image</a>` Works for JPG, GIF and PNG Files.
- filter
- re
- lightbox
- regular-expression