feat: introduce .env.example, docs

The example includes options that are expected to be changed. It also includes a reference to where in the docs you can find a full list of options.

ref: N25B-352

src/control_backend/agents/perception/vad_agent.py

@@ -166,9 +166,8 @@ class VADAgent(BaseAgent):
         """
         try:
             self.audio_out_socket = azmq.Context.instance().socket(zmq.PUB)
-            address = "inproc://vad_stream"
-            self.audio_out_socket.bind(address)
-            return address
+            self.audio_out_socket.bind(settings.zmq_settings.vad_pub_address)
+            return settings.zmq_settings.vad_pub_address
         except zmq.ZMQBindError:
             self.logger.error("Failed to bind an audio output socket after 100 tries.")
             self.audio_out_socket = None