Add notification and master upgrade docs.

Copy notification page over to new docs.
Add master upgrade documentation,
15 jobs for docs-upgrade-notification in 14 minutes and 16 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #100576
amd64
dispatcher-debian-10

00:02:24

passed #100578
amd64
dispatcher-debian-11

00:02:18

passed #100577
amd64
server-debian-10

00:02:51

passed #100579
amd64
server-debian-11

00:04:54

 
  Analyze
passed #100581
amd64
black

00:00:34

passed #100582
amd64
code_quality

00:00:23

passed #100583
amd64
coverage

00:06:26

59.27%
passed #100584
amd64
dockerfiles

00:00:19

passed #100586
amd64
pylint

00:03:00

passed #100580
amd64-dind
sast

00:02:14

passed #100585
amd64
schemas

00:00:32

 
  Build
passed #100588
amd64
debian/10

00:01:50

passed #100587
amd64
doc

00:00:42

passed #100589
amd64-dind
docker-amd64-dispatcher

00:02:02

passed #100590
amd64-dind
docker-amd64-server

00:02:53