add traefik network example

docs/deploying/reverse-proxy-traefik.md

@@ -13,6 +13,17 @@ You can setup auto renewing certificates with different kinds of [acme challenge
 ### Router configurations
 Add tuwunel to your traefik's network.
 
+```yaml
+services:
+    tuwunel:
+    # ...
+    networks:
+        - proxy # your traefik network name
+networks:
+    proxy: # your traefik network name
+        external: true
+```
+
 Be sure to change the `your.server.name` to your actual tuwunel domain. and the `yourcertresolver` should be changed to whatever you named it in your traefik config.
 
 You only have to do any one of these methods below.