Add initial super-resolution example script

[mcgibbon]

This PR adds an example script evaluating a nearest-neighbor super-resolution scheme with plots through fv3viz. It can serve as an entrypoint/introduction for @cynicalsavant 's work, showing some of the idiosyncracies of data loading and plotting with our tools, and demonstrating some of the ways an atmospheric scientist might want to see these models evaluated.

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[mcgibbon]

I'm also a little confused about how this code actually works. The upscaling is done by repeating the data along a new axis. Is this right? How is the data reshaped to remove this new axis?

apply_ufunc is a bit confusing, the code repeats the data along the existing core_dim axis when called. Not a new axis.