document updated gateway traffic route

README.md

@@ -90,7 +90,7 @@ The HTTP endpoints (shown below) will be fully functional at this point. You sho
 1. `GET /settings`. Gets current settings as JSON.
 1. `PUT /settings`. Patches settings (e.g., doesn't overwrite keys that aren't present). Accepts a JSON blob in the body.
 1. `GET /radio_configs`. Get a list of supported radio configs (aka `device_type`s).
-1. `GET /gateway_traffic/:device_type`. Starts an HTTP long poll. Returns any Milight traffic it hears. Useful if you need to know what your Milight gateway/remote ID is. Since protocols for RGBW/CCT are different, specify one of `rgbw`, `cct`, or `rgb_cct` as `:device_type.
+1. `GET /gateway_traffic(/:device_type)?`. Starts an HTTP long poll. Returns any Milight traffic it hears. Useful if you need to know what your Milight gateway/remote ID is. Since protocols for RGBW/CCT are different, specify one of `rgbw`, `cct`, or `rgb_cct` as `:device_type.  The path `/gateway_traffic` without a `:device_type` will sniff for all protocols simultaneously.
 1. `PUT /gateways/:device_id/:device_type/:group_id`. Controls or sends commands to `:group_id` from `:device_id`. Accepts a JSON blob. The schema is documented below in the _Bulb commands_ section.
 1. `POST /raw_commands/:device_type`. Sends a raw RF packet with radio configs associated with `:device_type`. Example body:
     ```