chore(helm): Add comments, clarifying ruler setup (#18607)

Co-authored-by: Jay Clifford <45856600+Jayclifford345@users.noreply.github.com>

docs/sources/setup/install/helm/reference.md

@@ -11321,7 +11321,7 @@ null
 		<tr>
 			<td>ruler.directories</td>
 			<td>object</td>
-			<td>Directories containing rules files</td>
+			<td>Directories containing rules files. If used, you must also configure `loki.rulerConfig.storage` to use local storage.</td>
 			<td><pre lang="json">
 {}
 </pre>

production/helm/loki/values.yaml

@@ -531,6 +531,11 @@ loki:
   rulerConfig:
     wal:
       dir: /var/loki/ruler-wal
+    # -- Storage for the ruler. If defining rules in `ruler.directories`, this must be configured to use local storage as shown below.
+    # storage:
+    #   type: local
+    #   local:
+    #     directory: /etc/loki/rules
   # -- Structured loki configuration, takes precedence over `loki.config`, `loki.schemaConfig`, `loki.storageConfig`
   structuredConfig: {}
   # -- Additional query scheduler config
@@ -3138,7 +3143,7 @@ ruler:
   # -- Set the optional grpc service protocol. Ex: "grpc", "http2" or "https"
   appProtocol:
     grpc: ""
-  # -- Directories containing rules files
+  # -- Directories containing rules files. If used, you must also configure `loki.rulerConfig.storage` to use local storage.
   directories: {}
   # tenant_foo:
   #   rules1.txt: |