Should these reply to the comment tagging tldr instead?
That would be possible to implement. Which way do you want it?
Also are there recursive? Can I tldr a comment or tldr itself?
According to the requirements of the bounty, link posts are supposed to be summarized, but I also added text posts. The program assumes the commenter mentioning tldr wants the root item summarized. Any duplicate mention on an item that has already been summarized will be ignored.