User Journey to create your first pipeline using GitOps

By supplementing existing docs, create a user journey/guide to a simple but complete pipeline using GitOps.

• Document overview using GitLab already built-in examples
• CI and CD difference, CI (build, test) and CD (deploy) pipelines
• New app should have Istio sidecar and Monitoring ready to use

GitLab ci.yaml with a readme for CI/CD, the pipeline and how it fits in with Big Bang.