Manage user packages site with pdm -g

[snowwm]

AFAIK, pdm add -g can only install packages to system python site (so it needs sudo).
I think it's cleaner to only install packages there with system package manager (e. g. pacman). I'd like to use pdm * -g as a way to manage user site, as with pip install --user.
If this isn't possible now, I propose adding a setting for it.

And great big thank you to @frostming for this awesome project!

[frostming]

AFAIK, pdm add -g can only install packages to system python site (so it needs sudo).

It depends on which python you choose for the global project, yes, pdm use -g to switch it. But anyway, I am fine with the improvement. Thank you.

[Hnasar]

Thank you! Just commenting for others who find this that the configuration option can be enabled with:

pdm config global_project.user_site True