Clarify why we call quit()

train.py

@@ -159,6 +159,7 @@ def load_train_eval_datasets():
         eval_dataset.save_to_disk("datasets/eval_dataset")
         
         # The `train_test_split` calls have put a lot of the datasets in memory, while we want it to just be on disk
+        # So we're calling quit() here. Running the script again will load the datasets from disk.
         quit()