Docs: recreates setup for oss alerting (#70156)
* recreates setup for oss alerting
* fixes relrefs
* fix relrefs
* fix relref
* adds other setup topics
* adds other setup topics 2
* adds other setup topics 3
* adds cloud setup
* adds cloud setup from legacy
* fixes links
* removing link
* gilles feedback
(cherry picked from commit 5fc6bf5c69)
Co-authored-by: brendamuir <100768211+brendamuir@users.noreply.github.com>