Add example notebook for the new regridding workflow

[LOCEANlloydizard]

Now that we have regridding option (Refs #726 and this PR, it would be nice to implement a notebook demonstrating how to use this new functionality in practice (e.g. from Sv computation to regridded outputs and plots) ?

[leewujung]

I agree - I wonder if it would be worthwhile to add this in addition to the compute_MVBS part in the getting started notebook, so that people can see how the 2 methods differ? also because regrinding is such a common procedure at the beginning of many workflows.