Argo CD tutorial: GitOps, sync, self-heal

Argo CD tutorialLearn Argo CD and GitOps: Applications, sync and health status, automated sync with prune and self-heal, sync waves, ApplicationSets and RBAC.Point it at a Git repo of manifests. Merge a change and the cluster follows; edit the cluster by hand and it puts things back. Each deploy becomes a pull request.Linux and systemd Home Alertmanager