Additiontal fields for os-release
Add a human readable name and and a bug report url, as suggested by https://www.freedesktop.org/software/systemd/man/os-release.html. Also see https://gitlab.com/freedesktop-sdk/freedesktop-sdk/merge_requests/687.
Qutebrowser displays the pretty name in the version information view, see https://github.com/qutebrowser/qutebrowser/pull/4865.