feedback collection: k8s configurations

Created by: slimsag

• https://sourcegraph.slack.com/archives/CJX299FGE/p1591127578463200
• https://docs.sourcegraph.com/admin/install/kubernetes/configure
• gitserver network changes / SSH keys
• using Sourcegraph with external Postgres/Redis
• nodeSelectors
• https://sourcegraph.slack.com/archives/CJX299FGE/p1583437361204200?thread_ts=1583437108.204100&cid=CJX299FGE
• RBAC
• Running users as root vs. non-root: https://github.com/sourcegraph/deploy-sourcegraph/tree/master/overlays/non-root
• Removing Prometheus due to k8s service discovery
• namespaced: https://github.com/sourcegraph/deploy-sourcegraph/tree/master/overlays/namespaced
• non-privileged deployment: https://github.com/sourcegraph/deploy-sourcegraph/tree/master/overlays/non-privileged