FR: jj config help should actually contain or point you to the config documentation

[jdmarshall]

Is your feature request related to a problem? Please describe.
jj config help makes no mention at all of the docs/config.md file

Describe the solution you'd like
Part of the problem here is that jj config list does not list any default values, and so the config options are largely undiscoverable. The first time someone tries to make a commit they get thrown into pico, and not everybody knows pico.

Part of the point of DVCS tools is I don't need an internet connection while working. That doesn't work if I have to google the contents of files that are already on my machine.

Describe alternatives you've considered
config help should mention more information is in the readme,

and, config list should be able to pull the canonical set of defaults so people know what can be set.

[martinvonz]

There's jj help -k config, which jj help --help points to. The problem is figuring out that that's where you're supposed to look. PRs to add pointers from e.g. jj help are welcome.