thanks for this!!
Hope this will solve my main annoyance with
Firefox:
sometimes I change Linux distro and then I lose all of my firefox settings, ("sync" would be better and keep flags changed by the users, but I don't think that the FF devs bother about it)
There is a user.js project on github[1] maintained by ghacks.net community members that provides a source of documentation for many settings. It's also useful as a way to monitor new and deprecated settings.
[1]: https://github.com/ghacksuserjs/ghacks-user.js