RFC: Additional git-for-each-repo synopsis

RFC: Additional git-for-each-repo synopsis

[Victor Engmark]

Hi all

git-for-each-repo is similar to a tool I wrote over a decade ago and
have been using ever since,
`fgit` <https://gitlab.com/victor-engmark/fgit/-/blob/master/fgit.sh>. 
Looking at the git-for-each-repo documentation it seems it's doing
things very differently, and I'm wondering if you would be interested
in an additional synopsis for the same command:

git for-each-repo <arguments> -- <directories>

For example, `git for-each-repo fetch -- ~/*/` would fetch in each
directory directly underneath the home directory. If some of the
directories are not repositories it can easily be amended to
`~/*/.git/..`, which is going to match only actual Git repositories on
sane systems. This is similar to the command I run every day or so,
`fgit pull -- ~/*/.git/.. ~/dev/*/.git/..
"/run/media/${USER}"/*/*/.git/..`.

This means not having to configure anything to use this tool. The
overhead of dealing with a configuration file is significant,
especially for beginners. It also means not having to go through
several steps every time my collection of repositories changes
(approximately weekly to monthly), and either coming up with some hack
for injecting all my repos into that configuration or forever second-
guessing whether the configuration is up to date. A third advantage is
that this would make it possible to use relative paths.

Cheers
Victor