Add comment regarding "no such host" issues when using `docker run`

README.md

@@ -49,6 +49,17 @@ $ docker run -e 'USERNAME=your_fritzbox_username' \
     fritzbox-prometheus-exporter:latest
 ```
 
+I've you're getting `no such host` issues, define your FritzBox as DNS server for your docker container like this:
+
+```bash
+$ docker run --dns YOUR_FRITZBOX_IP \
+    -e 'USERNAME=your_fritzbox_username' \
+    -e 'PASSWORD=your_fritzbox_password' \
+    -e 'GATEWAY_URL="http://192.168.0.1:49000"' \
+    -e 'LISTEN_ADDRESS="0.0.0.0:9042"' \
+    fritzbox-prometheus-exporter:latest
+```
+
 ### Using docker-compose
 
 Set your environment variables within the [docker-compose.yml](docker-compose.yml) file.