Update the Tavus example and comment about using the PERSONA_ID

examples/foundational/21-tavus-layer.py

@@ -39,7 +39,6 @@ async def main():
         tavus = TavusVideoService(
             api_key=os.getenv("TAVUS_API_KEY"),
             replica_id=os.getenv("TAVUS_REPLICA_ID"),
-            persona_id=os.getenv("TAVUS_PERSONA_ID", "pipecat0"),
             session=session,
         )
 

src/pipecat/services/tavus.py

@@ -35,7 +35,7 @@ class TavusVideoService(AIService):
         *,
         api_key: str,
         replica_id: str,
-        persona_id: str = "pipecat0",
+        persona_id: str = "pipecat0",  # Use `pipecat0` so that your TTS voice is used in place of the Tavus persona
         session: aiohttp.ClientSession,
         **kwargs,
     ) -> None: