There are several repositories that could be linked in the 5.2 Addon Manager that are not natively English. (Isotammi prefers Finnish and Swedish, GedcomforGeneanet prefers French, PersonFamilySearch prefers esperanto)
The Isotammi project has approved including (but deselected by default) their repository in built-in listings. In gramps.ini [Behavior], the addition to addons-projects would be: “, ['Isotammi project on GitHub', 'https://raw.githubusercontent.com/Taapeli/isotammi-addons/master/addons/gramps52', False]”
How can the help_url registration prefer the native language pages (which tend to be more comprehensive) over the English.