doc: kconfig: redirect: Add redirects for some old URLs

Documentation pages around Kconfig have moved around on a couple of
occasions in the past [1] [2] and current redirects were dysfonctional
(leading /) and incomplete, while an entire set of redirects was also
missing. This notably fixes the "browse latest development version of
this page" link on
https://docs.zephyrproject.org/2.7.5/guides/build/kconfig/tips.html or a
link to the "Kconfig tips" page as found in Kconfiglib's current README
(https://pypi.org/project/kconfiglib/

)

[1] commit 5342bc64 [2] commit
5c884184

Fixes #66701

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>