eclass is a file, as opposed to the package, which is a directory. So
doing `git -C eclass/foo.eclass log -- .` will fail because we can't
do "cd eclass/foo.eclass", which is what `-C` is trying to do.
This adds some scripts I have been using for over a year to deal with
the weekly package updates.
It comes with a `README.md` which describes a workflow similar to my
own.
The `sync_packages.sh` and `update_packages.sh` scripts are currently
not used anywhere. The idea behind them was to use them for Github
Action, but that will come as a follow-up PR.
