[Event Hubs] Add link of Event Hubs v5 IoT hub example code link in v1 example code (#10719)

Author: YijunXieMS

sdk/eventhub/azure-eventhubs/examples/iothub_recv.py

@@ -5,6 +5,9 @@
 
 """
 An example to show receiving events from an IoT Hub partition.
+This example is for Python Event Hubs SDK version 1.x.
+If you use the latest Event Hubs SDK version 5.x, the example code is
+at https://github.com/Azure/azure-sdk-for-python/blob/master/sdk/eventhub/azure-eventhub/samples/async_samples/iot_hub_connection_string_receive_async.py
 """
 from azure import eventhub
 from azure.eventhub import EventData, EventHubClient, Offset