What's the issue?

📚 Couldn't find any documentation for the quad utilities

Where did you find the issue?

Provide the location(s) of the issue: models/utilities/quad_utils_mod.f90

What needs to be fixed?

The quad utils are very important and extremely useful for doing interpolation in large models. The documentation of these utilities is missing. It should clearly distinguish between the different types of supported interpolation (e.g., regular, regular but nonuniform, irregular, dipole vs tripole, ...) and provide instructions on how to use them. Perhaps some example cases and developer tests would be nice.