Split docs for canary deployments and add use cases
What does this MR do?
Split docs for canary deployments and add use cases.
Builds upon https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/2357
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Split docs for canary deployments and add use cases.
Builds upon https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/2357