manual: rename section name of package lists

The original titles did no longer correspond with the actual menu names.
Additionally, choose a name that better reflects the fact that this is a
list.

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Acked-by: "Samuel Martin" <s.martin49@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>