MAINTAINERS: add and correct types of some "T:" entries
Tree location entries should start with the appropriate type.
Add git to some, hg to another.
Neaten tree type description.
Signed-off-by: Joe Perches <email@example.com>
Signed-off-by: Andrew Morton <firstname.lastname@example.org>
Signed-off-by: Linus Torvalds <email@example.com>