style(docs): format all docstrings to max 85 chars per line

Author: Pinaka07

pytorch_forecasting/data/_tslib_data_module.py

@@ -556,6 +556,7 @@ def _preprocess_data(self, idx: torch.Tensor) -> list[dict[str, Any]]:
         - The target data `y` and features `x` are converted to torch.float32 tensors.
         - The timepoints before the cutoff time are masked off.
         - Splits data into categorical and continous features, which are grouped based on the indices.
+
         """  # noqa: E501
 
         series = self.time_series_dataset[idx]