Add references to rules (salesforce_rules)

rules/salesforce_rules/salesforce_admin_login_as_user.yml

@@ -4,6 +4,7 @@ DisplayName: "Salesforce Admin Login As User"
 Enabled: true
 Filename: salesforce_admin_login_as_user.py
 Runbook: 'Please do an indicator search on USER_ID to find which user was assumed. '
+Reference: https://help.salesforce.com/s/articleView?id=sf.logging_in_as_another_user.htm&type=5
 Severity: Info
 Tests:
     - ExpectedResult: false