[bug#73055] [PATCH] doc: Explain `git format-patch` revision format

[Ekaitz Zarraga]

> The --base=auto can be dropped since it's part of our default git
> config, which is automatically installed for all of our contributors
> (c.f.: etc/git/gitconfig) when they build the Guix source.
>
> Otherwise, LGTM, if others think it has enough value to be added.
>
> --
> Thanks,
> Maxim

Hi!

Should we remove the --base=auto from all the examples or only mine?

Thanks!