Add boot-nfs.scr

Autogenerate a scr.uimg for a NFS rootfs boot.
Download nvidia binary drivers also
Add Alex's nouveau-env.sh
Add random notes to README.md
Add eth0 interface file

eth0 interface needs to be configured as 'manual' after nfs-boot.
This file needs to be put under /etc/network/interfaces.d/ when using
nfs rootfs.
Add flash-rootfs script