Update Hass.io docs

source/_addons/mosquitto.markdown

@@ -22,9 +22,19 @@ Set up a [mosquitto](https://mosquitto.org/) MQTT broker.
 }
 ```
 
+<p class='note'>Make sure you use logins and disable anonymous access if you want to secure the system.</p>
+
 Configuration variables:
 
 - **plain** (*Optional*): Listen to broker on port 1883 without SSL/TLS. Defaults to `true`.
 - **ssl** (*Optional*): Listen to broker on port 8883 with SSL/TLS. This requires certificates. Defaults to `false`.
 - **anonymous** (*Optional*): Allow anonymous connection. If *logins* is set, anonymous user can only read data. Defaults to `true`.
 - **logins** (*Optional*): A list of user that will be created with *username* and *password*.
+
+### {% linkable_title Home Assistant configuration %}
+
+```yaml
+# Example configuration.yaml entry
+mqtt:
+  broker: 172.17.0.1
+```