*** Package Lists Schema

The configs/profile/packages/ directory contains the package declarations for all ISOs.
The filename extension specifies the applicable target architecture (or '.all').
The package lists with filenames ending in '.all' will be installed for all architectures
whereas the architecture-specific package lists will be installed only for that architecture.
In any case, these packages will be installed only where the filename prefix applies.

An analagous set of package list files with the filename prefix 'cache-' repalcing 'packages-'
are supported for packages that are to be cached (but not installed)
in the /isorepo directory of offline-install ISOs (arg: '-O').

All of these package list files are strictly optional.
Any applicable package list files will be considered if they are found to exist at runtime.
Building with an empty configs/profile/packages/ directory would result in
an ISO with only the specified base package group installed ('base' by default).

* packages-all.<ARCH>
  => Installed in all ISOs.

* packages-all-gui.<ARCH>
  => Installed in all graphical ISOs exclusively.
  => e.g. args: '-E OpenRC/LXDE', '-E SystemD/Mate'

* packages-cli.<ARCH>
  => Installed in all CLI ISOs exclusively.
  => e.g. args: '-E OpenRC/CLI', '-E SystemD/CLI'

* packages-lxde.<ARCH>
  => Installed in all LXDE ISOs exclusively.
  => e.g. args: '-E OpenRC/LXDE', '-E SystemD/LXDE'

* packages-mate.<ARCH>
  => Installed in all Mate ISOs exclusively.
  => e.g. args: '-E OpenRC/Mate', '-E SystemD/Mate'

* packages-openrc.<ARCH>
  => Installed in all OpenRC ISOs exclusively.
  => e.g. args: '-E OpenRC/CLI', '-E OpenRC/LXDE'

* packages-openrc-gui.<ARCH>
  => Installed in all graphical OpenRC ISOs exclusively.
  => e.g. args: '-E OpenRC/LXDE', '-E OpenRC/Mate'

* packages-systemd.<ARCH>
  => Installed in all SystemD ISOs exclusively.
  => e.g. args: '-E SystemD/CLI', '-E SystemD/LXDE'

* packages-systemd-gui.<ARCH>
  => Installed in all graphical SystemD ISOs exclusively.
  => e.g. args: '-E SystemD/LXDE', '-E SystemD/Mate'