Make new tutorial on MOM5/MOM6 model grids and coordinates

[adele-morrison]

We are no longer going to have recipes with code to work for both MOM5 and MOM6. Instead we will add brief instructions to the top of each recipe to explain how users would convert on their own if needed. This tutorial will help by explaining B/C grids and tracer/velocity coords etc.

[navidcy]

I wanna be optimistic that I have the capacity to take this on... I wouldn't mind doing it in tandem with one more person?

[mmr0]

I'd like to help with this!

[navidcy]

There might be an xgcm object for MOM6 at https://mom6-analysiscookbook.readthedocs.io/en/latest/

[chrisb13]

I'm keen too!

[chrisb13]

@mmr0 and @navidcy we should about this today too.

[chrisb13]

There might be an xgcm object for MOM6 at https://mom6-analysiscookbook.readthedocs.io/en/latest/

Here.

Update: this only defines the Grid object but not the metrics.