More examples

[tomwhite]

One of the things that became apparent from AGU was that we need more examples!

Here are a few that I'd like to add:

• [x] Zarr. Read a regular Zarr array (using from_zarr), apply some array operations, then write the result out as Zarr (using to_zarr).
• [x] Xarray. Open a Zarr store as an Xarray Dataset, apply some array operations, then write the result out as Zarr.
• [x] Rechunk. Rechunk an Xarray Dataset. See #539
• [x] Icechunk. Same as the above, but using Icechunk.
• [ ] VirtualiZarr + Rechunk. Combine some NetCDF files using VirtualiZarr, rechunk (using Cubed), then save. See #646
• [ ] Single cloud machine. How to run Cubed on a single (large) cloud instance where we read/write from cloud storage, but intermediate data is stored on SSD.
• [ ] https://github.com/cubed-dev/cubed/issues/519