Intro to zarr notebook

[MathewBiddle]

• What is language(s) for used in the example?
  Python
• Is it focused on a particular module/software or an IOOS data service?
  Zarr
• Can you provide a minimum example of the expected code and results in a notebook?
  I think @ocefpaf has some

Please provide a detailed description of the suggested example below:
We should add an introduction to zarr notebook. Some things to include:

• Translating netCDF to zarr
• Creating zarr
• Working with zarr

[ocefpaf]

I probably have that already, just need to aggregate into a single notebook and create a story.

[ocefpaf]

xref.: #98

[ocefpaf]

Done in #131