Add a reference to flashing and booting so it can be used by minnowboard
and other boards.
Apply minor layout fixes.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Some files have moved from their original location, or are no longer
available. For the mbedtls samples, tweak the link to point to a page
where links for current and previous downloads can be found.
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>