docs: contribute: Suggest checking-out tags

To avoid unnecessary conflicts on pull and merge, suggest developers to
checkout tags, even when targeting mirror_ci/ branches.

Signed-off-by: Jorge Marques <jorge.marques@analog.com>

Author: gastmaier

docs/ci.rst

@@ -44,6 +44,13 @@ provided (``mirror_ci/<remote-name>/<branch>``):
 
 When upstreaming a driver, target the pull-request against the mirror.
 
+.. attention::
+
+   Do **not** base your work on the head of the ``mirror_ci/*``, it is
+   frequently force pushed either by upstream (they are testing branches after
+   all). Instead, find a common stable base, for example the previous tag such
+   as `v6.19-rc1 <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.19-rc1&id=8f0b4cce4481fb22653697cced8d0d04027cb1e8>`__
+
 All of them are mirrors from the links shown with a single commit on top
 that includes the CI workflows, :git-linux:`as simple as <ci:.github/workflows/mirror.yml>`:
 

docs/contribute.rst

@@ -175,6 +175,16 @@ conventions, and lifecycle, helping maintain modularity and clarity. For an
 up-to-date map of these subsystems and their interfaces, see
 :external+upstream:doc:`subsystem-apis`.
 
+When developing for a particular subsystem, look for the appropriate git tree
+in the :git-linux:`MAINTAINERS` file to work on. Development branches may be
+force pushed. It is reasonable to base you work on top of the current latest
+tag, such as `v6.19-rc1
+<https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.19-rc1&id=8f0b4cce4481fb22653697cced8d0d04027cb1e8>`__
+or near it, this avoids unnecessary merge commits when pulling changes.
+
+For some subsystems, CI/CD is automatically applied to developemnt branches as
+described at :ref:`ci`.
+
 IIO Subsytem
 ~~~~~~~~~~~~