Update index.md

Remove `fsspec` from `xr.open_dataset` usage example.

docs/index.md

@@ -59,14 +59,9 @@ virtual_ds.virtualize.to_kerchunk('combined.json', format='json')
 Now you can open your shiny new Zarr store instantly:
 
 ```python
-fs = fsspec.filesystem('reference', fo='combined.json')
-m = fs.get_mapper('')
-
-ds = xr.open_dataset(m, engine='kerchunk', chunks={})  # normal xarray.Dataset object, wrapping dask/numpy arrays etc.
+ds = xr.open_dataset('combined.json', engine='kerchunk', chunks={})  # normal xarray.Dataset object, wrapping dask/numpy arrays etc.
 ```
 
-(Since we serialized the cached results using the kerchunk specification then opening this zarr store still requires using fsspec via the kerchunk xarray backend.)
-
 No data has been loaded or copied in this process, we have merely created an on-disk lookup table that points xarray into the specific parts of the original netCDF files when it needs to read each chunk.
 
 See the [Usage docs page](#usage) for more details.