Added a walkthrough guide.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
(cherry picked from commit 8b2afbb6b44480f87128ab310ad0ce134b98161b)
walkthrough: Removed reference to access levels in Hooks/

Signed-off-by: Martin Stone <martin@d7415.co.uk>
createdb: Access levels were wrong for importing from legacy version.

Signed-off-by: Martin Stone <martin@d7415.co.uk>
createdb.py: Added guidance on access levels used during legacy upgrade to help output.

Signed-off-by: Martin Stone <martin@d7415.co.uk>