Addon Manager listing is broken - shows 404 error

[NeatNit]

In the Addon Manager built into FreeCAD, this addon is listed, but if you click it you get an error. See comparison with OpenThemes in the table below:

In addons list	After clicking

I tried looking around but I don't really see any reason why this fails. Hope you can figure it out.

Note: I came across this maybe a month ago and brought it up on the FreeCAD discord, but I don't remember opening an issue for it.

[Hecatron]

It looks like it's referencing an incorrect link
https://github.com/FreeCAD/FreeCAD-library/archive/refs/heads/master.zip/raw/master/README.md

Although I don't know how that link is calculated by FreeCad, the /raw/master/README.md after the .zip part looks wrong
I think the addon index is located here
https://github.com/FreeCAD/Addons/blob/main/Data/Index.json

[chennes]

This repo needs a package.xml file added: see https://freecad.github.io/Addon-Academy/Topics/Structuring/Manifest/