update RRR tutorials

Author: yzhang511

notebooks/reduced-rank-model-example.ipynb

@@ -35,11 +35,7 @@
     "from lightning.pytorch import Trainer\n",
     "from lightning.pytorch.callbacks import ModelCheckpoint\n",
     "\n",
-    "from models.decoders import (\n",
-    "    MultiRegionReducedRankDecoder,\n",
-    "    MultiSessionReducedRankDecoder,\n",
-    "    ReducedRankDecoder,\n",
-    ")\n",
+    "from models.decoders import ReducedRankDecoder\n",
     "\n",
     "from utils.config_utils import config_from_kwargs, update_config\n",
     "from utils.data_loader_utils import SingleSessionDataModule\n",