remove reference to the old location

Author: TomNicholas

_toc.yml

@@ -46,7 +46,6 @@ parts:
         sections:
           - file: intermediate/indexing/advanced-indexing.ipynb
           - file: intermediate/indexing/boolean-masking-indexing.ipynb
-      - file: intermediate/hierarchical_computation.ipynb
       - file: intermediate/xarray_and_dask
       - file: intermediate/intro-to-zarr.ipynb
       - file: intermediate/storage_formats.ipynb