Adds missing code-sample directive to the Hello World sample in
preparation for upcoming changes to the Zephyr documentation that will
be leveraging the provided description and metadata.
Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
Replaces inaccurate or wrong vendor prefixes in board and soc
folder names with those from thr vendor prefix file
Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>