optimize format for access control doc. (#1501)

content/docs/tasks/security/basic-access-control.md

@@ -15,8 +15,8 @@ This task shows how to control access to a service using the Kubernetes labels.
 
 * Deploy the [Bookinfo](/docs/guides/bookinfo/) sample application.
 
-*   Initialize the application version routing to direct `reviews` service requests from
-    test user "jason" to version v2 and requests from any other user to v3.
+* Initialize the application version routing to direct `reviews` service requests from
+  test user "jason" to version v2 and requests from any other user to v3.
 
     ```command
     $ istioctl create -f @samples/bookinfo/routing/route-rule-all-v1.yaml@
@@ -25,26 +25,26 @@ This task shows how to control access to a service using the Kubernetes labels.
     Save the following YAML snippet as `route-rule-reviews-jason-v2-v3.yaml`:
 
     ```yaml
-    apiVersion: networking.istio.io/v1alpha3
-    kind: VirtualService
-    metadata:
-      name: reviews
-    spec:
-      hosts:
-        - reviews
-      http:
-      - match:
-        - headers:
-            cookie:
-              regex: "^(.*?;)?(user=jason)(;.*)?$"
-        route:
-        - destination:
-            host: reviews
-            subset: v2
-      - route:
-        - destination:
-            host: reviews
-            subset: v3
+        apiVersion: networking.istio.io/v1alpha3
+        kind: VirtualService
+        metadata:
+          name: reviews
+        spec:
+          hosts:
+          - reviews
+          http:
+          - match:
+            - headers:
+                cookie:
+                  regex: "^(.*?;)?(user=jason)(;.*)?$"
+            route:
+            - destination:
+                host: reviews
+                subset: v2
+          - route:
+            - destination:
+                host: reviews
+                subset: v3
     ```
 
     and then run the following command: