I really like this Phabricator walkthrough as something I can point new contributors to, however, I think that it would be better to recommend moz-phab over arc diff.

mars - is this something you can look at when you have time?

I'll pick this up today.

Update the walkthrough to use moz-phab. Also update examples and
screenshots to use real Firefox source tree information.

Done! https://moz-conduit.readthedocs.io/en/latest/walkthrough.html