Update 'Automatic' policy value creation explanation

Clarified the description of the 'Automatic' policy value creation mode, specifying the behavior for primary and sub-policy types.

Author: cbruno10

docs/concepts/policies/values-settings.md

@@ -43,7 +43,7 @@ policy values exist only on the target.
 Policy value creation is controlled by the `Turbot > Materialization` policy, which supports two modes:
 
 - **Always**: Policy values are created for all resources regardless of whether policy settings exist. This provides comprehensive coverage but may impact performance in large environments.
-- **Automatic**: Policy values are only created when you explicitly set a policy setting somewhere in the resource hierarchy. For example, if no policy setting exists for `AWS > S3 > Bucket > Approved` at the AWS account level, then S3 buckets in that account will not have policy values for `AWS > S3 > Bucket > Approved` or its sub-policies.
+- **Automatic**: Primary policy values are only created when you explicitly set a primary policy in the resource hierarchy. For sub-policy types, their values are also created when a related primary policy setting is created. For example, if no policy setting exists for `AWS > S3 > Bucket > Approved` at the AWS account level, then S3 buckets in that account will not have policy values for `AWS > S3 > Bucket > Approved` or its sub-policies.
 
 Note that some policy types, such as those related to CMDB and event handler configuration, always create values when resources are discovered, regardless of the materialization mode.