Update doc

Author: krishung5

README.md

@@ -736,6 +736,9 @@ class TritonPythonModel:
         return None
 ```
 
+*Note:*: If `response_sender` is reused across multiple requests, the model must
+ensure that the `response_sender` is properly cleaned up for the rescheduled requests.
+
 ### `finalize`
 
 Implementing `finalize` is optional. This function allows you to do any clean