Add some documentation files to the corresponding machine sections
and mention the machine names in the section titles where it is
not so obvious (e.g. that "taihu" is a 405 machine).

Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Message-Id: <20220105104800.407570-1-thuth@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>