docs: Move the python libraries to tools/lib/python

"scripts/lib" was always a bit of an awkward place for Python modules.  We
already have tools/lib; create a tools/lib/python, move the libraries
there, and update the users accordingly.

While at it, move the contents of tools/docs/lib.  Rather than make another
directory, just put these documentation-oriented modules under "kdoc".

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251110220430.726665-2-corbet@lwn.net>

.pylintrc

@@ -1,2 +1,2 @@
 [MASTER]
-init-hook='import sys; sys.path += ["scripts/lib/kdoc", "scripts/lib/abi", "tools/docs/lib"]'
+init-hook='import sys; sys.path += ["tools/lib/python"]'