feat(postgres): add shared database deployments

postgres/k8s/secrets.yaml.example

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: Secret
+metadata:
+  name: postgres-shared-secrets
+  namespace: database
+type: Opaque
+stringData:
+  POSTGRES_ADMIN_PASSWORD: ""
+  AUTHENTIK_DB_PASSWORD: ""
+  GITEA_DB_PASSWORD: ""
+  NETRONOME_DB_PASSWORD: ""
+  PENPOT_DB_PASSWORD: ""