Add usage example.

README.md

@@ -52,6 +52,21 @@ ECMWF data products are subject to the following terms:
 3. Licence Statement: ECMWF data is published under a Creative Commons Attribution 4.0 International (CC BY 4.0). https://creativecommons.org/licenses/by/4.0/
 4. Disclaimer: ECMWF does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use.
 
+## Usage
+Use the Huggingface Hub file system to load files. The `datasets` library doesn't support netCDF files yet.
+
+```python3
+from huggingface_hub import HfFileSystem
+import xarray
+
+fs = HfFileSystem()
+
+files = fs.ls("datasets/shermansiu/dm_graphcast_datasets/dataset", detail=False)
+
+with fs.open(files[0], "rb") as f:
+    example_batch1 = xarray.load_dataset(f).compute()
+```
+
 ## Citation
 - Paper: https://www.science.org/doi/10.1126/science.adi2336
 - Preprint: https://arxiv.org/abs/2212.12794