add init

Author: rongkunxue

ding/entry/__init__.py

@@ -26,3 +26,4 @@
 from .serial_entry_mbrl import serial_pipeline_dyna, serial_pipeline_dream, serial_pipeline_dreamer
 from .serial_entry_bco import serial_pipeline_bco
 from .serial_entry_pc import serial_pipeline_pc
+from .serial_entry_episode import serial_pipeline_episode