Draft: generate installer images for laptops
This is somewhat hacky, but the idea is to basically implement a bunch of defaults and produce a pmOS image with the sole purpose of installing a second pmOS image.
You're expected to do a normal "pmbootstrap install" first to generate
the actual image you want to installer. then run pmbootstrap install --installer
to build an installer image for it.
the installer will always use GNOME, no matter what your target DE is.