Update __init__.py for MD22 compatibility

Author: guillemsimeon

torchmdnet/datasets/__init__.py

@@ -4,6 +4,7 @@
 from .custom import Custom
 from .hdf import HDF5
 from .md17 import MD17
+from .md22 import MD22
 from .qm9 import QM9
 from .qm9q import QM9q
 from .spice import SPICE
@@ -21,6 +22,7 @@
     "GDB10to13",
     "HDF5",
     "MD17",
+    "MD22",
     "QM9",
     "QM9q",
     "S66X8",