Enable branch protection automation for ARI WG

- refer to [rfc-0015-branch-protection.md](https://github.com/cloudfoundry/community/blob/main/toc/rfc/rfc-0015-branch-protection.md)

Author: stephanme

toc/working-groups/app-runtime-interfaces.md

@@ -458,4 +458,6 @@ areas:
   - cloudfoundry/notifications
   - cloudfoundry/app-runtime-interfaces-infrastructure
 
+config:
+  generate_rfc0015_branch_protection_rules: true
 ```