Improve the visibility of non-Flathub Flatpak & non-Flatpak installation methods for clients #3224
Description
Currently, even though some clients (e.g., Commet) have metadata related to non-Flathub Flatpak and non-Flatpak installation methods, we don't display this information. This can, and has led, to people thinking that a client isn't available on their platform. I think we should improve on this matter.