Documentation: what does "git log --indexed-objects" even mean?

Documentation: what does "git log --indexed-objects" even mean?

4fe10219 (rev-list: add --indexed-objects option, 2014-10-16) adds
"--indexed-objects" option to "rev-list", and it is only useful in
the context of "git rev-list" and not "git log".  There are other
object traversal options that do not make sense for "git log" that
are shown in the manual page.

Move the description of "--indexed-objects" to the object traversal
section so that it sits together with its friends "--objects",
"--objects-edge", etc. and then show them only in "git rev-list"
documentation.

Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>