User Migration Support

[TomCasavant]

Eventually I assume glitch will bring back custom domains (https://help.glitch.com/hc/en-us/articles/16287558909965-Adding-a-Custom-Domain) and when they do I'll probably want to switch domains to something else

Currently we can export/import bookmarks from a profile but ideally we could set up some sort of migration so people I follow/follow me will be transferred to the new domain.

I don't know how difficult that'd be, I know mastodon sets up some sort of redirect from the old profile to the new profile and then followers are removed when they get added to the new profile