fix(docs): add required line to attributes

Author: tembleking

website/docs/r/secure_vulnerability_policy.md

@@ -47,6 +47,8 @@ resource "sysdig_secure_vulnerability_policy" "vulnerability_policy_example" {
 
 ## Attributes Reference
 
+In addition to all arguments above, the following attributes are exported:
+
 * `identifier` - The external identifier computed after creation.
 
 ## Import