bug#69786: [PATCH] docs: mention the keymap to add keybindings to for term-mode

[Eli Zaretskii]

> From: Konstantin Kharlamov <Hi-Angel@yandex.ru>
> Cc: 69786@debbugs.gnu.org
> Date: Thu, 14 Mar 2024 10:23:32 +0300
> 
> …with that said, if we have to put that to the mode documentation and
> not to the manual, I think a more appropriate place might be docs for
> `term-mode-map` and `term-raw-map` accordingly.  This is a place where
> I would have looked after finding out that my custom keyindings do not
> work.

We can do that as well, sure.  But that alone is not enough because
the information will then be less discoverable.