Docs - product feedback: add fully featured documentation for GitLab persistence

Like a DevOps I don't want to set up default storage class in the cluster, instead I want to have a concrete example where I can see the all places where I need to put a custom storage class. In the documentation there is such a file - https://gitlab.com/gitlab-org/charts/gitlab/-/blob/master/examples/storage/helm_options.yml But it is not enough as there are also prometheus and zoekt components which also has persistency.