We wish for flathub.org
to provide a mechanism for developers to log in and
manage their flatpaks and later payment mechanisms etc. Later we will want
non-developers to also be able to log in, in order to manage their subscriptions
or sponsorships etc.
To that end we need the concept of users on flathub.org and to tie that to some authentication mechanism(s). Since developers must have a Github account in order to have submitted a flatpak to flathub, we can use Github to authenticate