Improve docs and sync helm charts' crd

charts/postgres-operator/crds/postgresqls.yaml

@@ -495,13 +495,17 @@ spec:
                     type: string
                   standby_primary_slot_name:
                     type: string
-                oneOf:
+                anyOf:
                 - required:
                   - s3_wal_path
                 - required:
                   - gs_wal_path
                 - required:
                   - standby_host
+                not:
+                  required:
+                    - s3_wal_path
+                    - gs_wal_path
               streams:
                 type: array
                 items:

docs/reference/cluster_manifest.md

@@ -479,7 +479,8 @@ Note that `s3_wal_path` and `gs_wal_path` are mutually exclusive.
 
 * **standby_primary_slot_name**
   name of the replication slot to use on the primary server when streaming
-  from a remote primary. Optional.
+  from a remote primary. See the Patroni documentation
+  [here](https://patroni.readthedocs.io/en/latest/standby_cluster.html) for more details. Optional.
 
 ## Volume properties