refactor(datasets): module cleanup (#3169)

src/lerobot/datasets/lerobot_dataset.py

@@ -596,7 +596,7 @@ class LeRobotDataset(torch.utils.data.Dataset):
               the dataset from that address and load it, pending your dataset is compliant with
               codebase_version v3.0. If your dataset has been created before this new format, you will be
               prompted to convert it using our conversion script from v2.1 to v3.0, which you can find at
-              lerobot/datasets/v30/convert_dataset_v21_to_v30.py.
+              lerobot/scripts/convert_dataset_v21_to_v30.py.
 
 
         2. Your dataset doesn't already exists (either on local disk or on the Hub): you can create an empty
@@ -1683,7 +1683,6 @@ class LeRobotDataset(torch.utils.data.Dataset):
         if image_writer_processes or image_writer_threads:
             obj.start_image_writer(image_writer_processes, image_writer_threads)
 
-        # TODO(aliberts, rcadene, alexander-soare): Merge this with OnlineBuffer/DataBuffer
         obj.episode_buffer = obj.create_episode_buffer()
 
         obj.episodes = None