I would like to extend the link tool in the TinyMCE editor so that an editor can add a custom html-attribute (i.e. rel="nofollow"). I found this get repo which gave me some inspiration but I can't get my head around how to custimize the editor. Also this repo is targeted againt the older version of TinyMCE.
https://github.com/mariajemaria/ExtendedEPiLink
I'm using Episerver 11.10.