* Fix description of kolla_base_distro
* Update support matrix notes

Change-Id: Ibc2b9b647766231029fdc2c0e3671e872b1ae366

CentOS Stream 8 support has been dropped. Migration path will be present
in Yoga release - as a followup change.

MichaelRigart.interfaces does not support custom routes for
NetworkManager yet. It has been disabled in CI for Rocky Linux 9
temporarily.

Non-voting CentOS Stream 9 CI overcloud job is using RL9 container
images (as kolla CI is not building CS9 images anymore).

Change-Id: Idf5ee822b03ba40179803c981500a6bad37594bf

Co-Authored-By: Bartosz Bezak <bartosz@stackhpc.com>

Change-Id: I06a3e9922cf95979f3bca120cd82633046270fa3

Change-Id: If7d6e58b19f98ccb7cc4c209e458cb6f4f4765ad

Change-Id: I0747cc8fa6fdbfa980b1263da3b3edddb725d2db

Change-Id: I3c4d81f59bb61fdd23234777b8d839adecfe86f2
Story: 2004960
Task: 42324

Change-Id: Ie8fdaf95fc6fa54430e5f3acb97ae2f0474437e7

Adds a support matrix page to documentation.

Change-Id: Ie42900d89afff40b8a12364b38de9854ed817275
Story: 2006574
Task: 39552