Add the description of option 'b' to indicate the boot device including
the bootable image.
Tracked-On: #1917
Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Reorganize the high-level design docs to align with a work-in-progress
HLD document. Migrate previous web content (and images) into the new
organization.
From here we'll continue inclusion of new design chapters as they're
reviewed and edited.
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>