README: Add simple README file
examples: Add example files

This adds two example wrapper scripts, and documents them in the README.

Signed-off-by: Sean Cross <xobs@kosagi.com>
novena-image: Improve real-disk, package list reliability

We now properly write to real disks, and don't fail if no U-Boot is
specified.  Additionally, the package list is now properly parsed.

Signed-off-by: Sean Cross <xobs@kosagi.com>