Clarify what is meant by "Support UGRID"

[lesserwhirls]

As mentioned at the meeting today, we should clarify what is meant by supporting UGRID.

Triangle, quad, hex, meshes? Full 3D unstructured topology?

For sure, support output from FVCOM , ADCIRC, SCHISM. Anything else? Please add pointers to samples here.

[yosoyjay]

In the meeting it was proposed to focus on support for triangular meshes initially because that's the discretization used by the "backbone" models.

However, there are some models such as DELFT3D and SCHISM that allow for hybrid mesh in the horizontal and MPAS uses hexes.

I believe we chose to hold on supporting fully unstructured in 3D.

[lesserwhirls]

That's what I recall as well. I've updated #4 with a list of samples to capture.