in own webserver doc link to nginx fronting traefik example

docs/configuring-playbook-own-webserver.md

@@ -143,6 +143,8 @@ devture_traefik_additional_entrypoints_auto:
     config: {}
 ```
 
+For an example where the playbook's traefik is fronted by Nginx running on the same server, see [Nginx reverse-proxy fronting playbook's Traefik](../examples/nginx/README.md).
+
 (Deprecated) **For `matrix-nginx-proxy`** fronted by another reverse-proxy, you would need some configuration like this:
 
 ```yaml