The documentation says that "screenshots should have a 16:9 aspect ratio", but it's not clear how to actually make app screenshots with this aspect ratio on Linux.

There used to be a Gnome extension, but the extension has not been updated in 5 years and do not work with later versions of Gnome. It's also not a option for other environments.

If aspect ratio 16:9 is preferable, please update the documentation with some guidance on how this can be done so that we can start update the many outdated/suboptimal screenshots. Ideally using some environment agnostic method.