Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
I just found out there's a gnome-extensions tag.
I think it's just a synonym of the older and well-documented gnome-shell-extension tag. So gnome-extensions should be merged with gnome-shell-extension.
I have suggested a tag synonym.