add metadata

[kernel] enable driver for GPIO expander

make a desktop version (closes #1)

split multistrap.conf into multiple sections

tweaks

upgrade to debian stretch

* add required packages not installed by default (systemd udev)
* disable predictable network interfaces name through net.ifnames=0
* execute dpkg config on first boot instead of a cross-arch chroot
* add google's dns server for debugging purposes (eg. systemd fails)

add setup script