Add volumeSnaphot for ttrss postgresql

ttrss/postgres-snapshot.yaml

@@ -0,0 +1,8 @@
+apiVersion: snapshot.storage.k8s.io/v1
+kind: VolumeSnapshot
+metadata:
+  name: postgres-csi-volume-snapshot-longhorn-backup
+spec:
+  volumeSnapshotClassName: longhorn-backup-vsc
+  source:
+    persistentVolumeClaimName: data-ttrss-postgresql-0