docs(adt): add faq

Author: nerda-codes

faq/audit-trail.mdx

@@ -27,3 +27,7 @@ Audit Trail is free of charge.
 ## Which Scaleway resources are integrated with Audit Trail?
 
 During Beta, only Secret Manager is integrated with Audit Trail. Refer to the [dedicated documentation](/identity-and-access-management/audit-trail/reference-content/resource-integration-with-adt/) to find out more about resource integration with Audit Trail.
+
+## Where are my Audit Trail events stored?
+
+Audit Trail events are stored in the same region where the activity occurred. This means that if an event takes place in a specific region, it will be saved and accessible in that same region.