Merge branch 'mjang-doc-add-link-to-feature-flag' into 'master'

Add link to feature flag instructions

See merge request gitlab-org/gitlab!42748

doc/administration/audit_events.md

@@ -183,6 +183,7 @@ the steps bellow.
 
 CAUTION: **Warning:**
 This feature might not be available to you. Check the **version history** note above for details.
+If available, you can enable it with a [feature flag](#enable-or-disable-audit-log-export-to-csv).
 
 Export to CSV allows customers to export the current filter view of your audit log as a
 CSV file,