feature(xrk): add q-transformer

ding/entry/__init__.py

@@ -25,4 +25,4 @@
       import serial_pipeline_preference_based_irl_onpolicy
 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_pc import serial_pipeline_pc

ding/model/template/__init__.py

@@ -29,3 +29,4 @@
 from .qgpo import QGPO
 from .ebm import EBM, AutoregressiveEBM
 from .havac import HAVAC
+from .qtransformer import QTransformer