Document end to end flow for Kubernetes+Auto DevOps

Deployment flow

We need more clear documentation with screenshots etc, and how-tos of the end to end flow documented. Where is the cluster creation + how to leverage Auto DevOps to drive deployments to GKE?

Steps:

1. Create Google account and register for trial
2. Enable a few Google APIs (check https://gitlab.com/gitlab-org/gitlab-ce/issues/44685 first)
3. Create project from template
4. In the project settings, a new Kubernetes cluster is created on GKE using our integration
5. Install Tiller, ingress, prometheus
6. Get IP and enable Auto DevOps from the project settings
   • Add base domain 1.2.3.4.nip.io
   • Choose deployment strategy
7. Pipeline is run for the first time
8. Create MR with a change to test review apps
9. Merge MR > check staging > rollout to prod
10. Monitor using the Environments feature: https://docs.gitlab.com/ce/ci/environments.html