Hi Orionik,
I have provided some maintenance for another add-on by Calia.
It took me a very long time to get in touch with her, but you may be able to contact her via her Discord channel.
After that, I would suggest you talk to the administrator of this site.
The original author's GitHub repository is following.
https://github.com/Flamage82/Librarian
But it does not seem to reflect any version since Calia provided maintenance.
It might be best you fork this repository and update it sequentially to the latest release version and commit your patches from there.
- Calamath