Adding the livekit_config parameter to docstring.

Author: filipi87

src/pipecat/services/heygen/api_liveavatar.py

@@ -79,6 +79,7 @@ class LiveAvatarNewSessionRequest(BaseModel):
         video_settings (VideoSettings): Video encoding settings.
         is_sandbox (bool): Enable sandbox mode (default: False).
         avatar_persona (AvatarPersona): Avatar persona configuration.
+        livekit_config (CustomSDKLiveKitConfig): Custom LiveKit configuration.
     """
 
     mode: str = "LITE"