Make configuration documentation internal
This moves the documentation for the configuration from the README
to a file embedded in the extension. This means you can do something like:
$ hg help config.hggit.retries
"hggit.retries"
Interacting with a remote Git repository may require authentication.
Normally, this will trigger a prompt and a retry, and this option
restricts the amount of retries. Defaults to 3.
This is slightly harder to achieve on Python 3.6, so this builds on !187 (merged) that drops support for it.
Edited by Dan Villiom Podlaski Christiansen