fetch: elaborate --depth action
fetch: elaborate --depth action

--depth is explained as deepen, but the way it's applied, it can
shorten the history as well. Keen users may have noticed the
implication by the phrase "the specified number of commits from the
tip of each remote branch". Put "shorten" in the description to make
it clearer.

Signed-off-by: Nguyễn Thái Ngọc Duy <024f400cd820cb2ddbe54c7fecfd01e45f30bb96@gmail.com>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git