Adding clarification to auditIfNotExist ExistenceScope for ResourceGroup

Author: shanhix1

articles/governance/policy/concepts/effects.md

@@ -279,8 +279,7 @@ related resources to match.
   - Allowed values are _Subscription_ and _ResourceGroup_.
   - Sets the scope of where to fetch the related resource to match from.
   - Doesn't apply if **type** is a resource that would be underneath the **if** condition resource.
-  - For _ResourceGroup_, would limit to the **if** condition resource's resource group or the
-    resource group specified in **ResourceGroupName**.
+  - For _ResourceGroup_, would limit to the resource group in **ResourceGroupName** if specified. If **ResourceGroupName** isn't specified, would limit to the **if** condition resource's resource group, which is the default behavior.
   - For _Subscription_, queries the entire subscription for the related resource. Assignment scope should be set at subscription or higher for proper evaluation.
   - Default is _ResourceGroup_.
 - **EvaluationDelay** (optional)