Figure out a way to make domain.com/user urls work
Mastodon has the domain.com/@user domains, but the @ is a rather unfamiliar part of a domain name. GNU Social has always had the domain.com/user urls, but that involves restricting usernames and reserving some special routes, as well as maybe invalidating existing names later once we need a new 'special route' (e.g. 'settings').
One solution would be to put all the pleroma routes under domain.com/p/..., so we'd only need to reserve the 'p' username (which is illegal anyway). This would make it possible to use all other routes for usernames.