Add missing files and dirs to 00-INDEX in Documentation/

Add descriptions for a number of missing files and directories to the
Documentation/00-INDEX file.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>