Predefined categories aren't a great way for organizing installed
applications, but they have their use in "stores" like Software
or flathub.
Not listing any category means we fall through the cracks, so
pick the (hopefully) least inappropriate one ...
https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1160
(cherry picked from commit 360f5b1642)
We finally have everything in place for distributing the Extensions app
as flatpak without jumping through too many hoops. Add a manifest that
can produce a nightly build like other GNOME modules, and can serve as
a template for a stable manifest on flathub.
https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1133
The Extensions app code is now independent enough from the rest of the code
base to move it to its own subprojects, like we did for the extensions-tool.
This allows for stand-alone builds of the app, which we are about to use
for distributing it as flatpak.
https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1133
