Add a flatpak manifest in-tree

[bilelmoussaoui]

This is mostly a request to add a flatpak manifest for building the application for development purposes. Currently there's a top support from GNOME Builder & I have wrote a very basic extension for vscode as well.

The manifest could be used for CI as well, there's a pretty simple Github Action that builds & creates a bundle for each commit to make testing much easier for users.

[ids1024]

I've seen mention of how this can help with things like Gnome builder.

How would this work with Flathub? Would https://github.com/flathub/com.system76.popsicle just end up with a duplicate copy of the same manifest?

[bilelmoussaoui]

From Flathub, there's nothing that can be done at the moment. As in general those manifests tend to be a bit different and build the current commit instead of the latest stable release. So for now it could just provide a CI to test that the flatpak build is always working & lower the barrier a bit to contribute to such apps.

Though, in the future, there could be some kind of integration that would allow you to get a token that you fed to the github action and it pushes that to ostree repository like Flathub (for stable/beta releases only for now). That what Firefox does currently.