Clarify script section in README

Updated the README to clarify the script section.

Author: Its-Nmk

Server-Side Components/Business Rules/Update Set Scope Validation/README.md

@@ -35,8 +35,11 @@ This business rule is useful for ensuring that updates in an update set adhere t
 Use the following script in the **Script** field:
 
 ```javascript
+(function executeRule(current, previous /*null when async*/) {
+
+	// Add attached code here
 
-// Add Attached code here
+})(current, previous);
 
 ```
 
@@ -47,4 +50,4 @@ Use the following script in the **Script** field:
 
 
 ## Screenshots
-![Output Result](error.png)
+![Output Result](error.png)