Since version 0.9.4, OSM Smart Menu allows users to add new maps (if they are automatically recognized).
Not sure where to start? Give it a try with OsmHydrant.
PS: A handy link to the configuration page was added in version 0.10.0
Comment from jidanni on 3 July 2020 at 06:50
Say, will sites I add propagate to all the computers I have chromium installed on?
Comment from jgpacker on 3 July 2020 at 20:14
Unfortunately not yet, but it’s on the backlog! :-)