Data storage page: add some example commands

[paigem]

Add some lines for eg xarray save as netcdf/zarr

[hot007]

Oh dear, sorry folks, I accidentally added this on Main branch instead of my fork. See commit

However, there is clear need to link the modified paragraph (where I say "see Tools section") with Paola's new work over there, so @paolap may wish to update that link to go to exactly where dask chunking is discussed once she does her pull request.