Animated checkmark on final page
Split out from #8 (closed). Two variations on the theme from @jimmac, one in video form and one in HTML form:
https://teams.pages.gitlab.gnome.org/Design/web-experiments/initial-setup-done
For 3.36 we just added a static version of the checkmark. It's unclear (to me) what the best approach to showing an animation would be – embed a WebM with alpha channel? web view with an SVG? artisan animation using GTK?