title: What is "ESP_NOW_ROLE_MAX"?
body: <p>While trying out esp-now on a nodemcu v1.0 (esp-12e) I stumbled across <code>ESP_NOW_ROLE_MAX</code> while setting the role with <code>esp_now_set_self_role(...)</code> and wondered what this could be? Any idea? (I was using Platform.io, but this should also be the same in Arduino IDE)</p>