Cup as VolumeUnit

[neutmute]

Hi again!
I'm working on a food nutrition system and we need to be able to reference the volume unit of cup (see wiki def).

UnitsNet.Unit.VolumeUnit has Teaspoonand Tablespoon but no Cup.

I propose adding:

• MetricCup (250mL)

I don't need US Cups for now but would be happy to add to help clarify the distinction. There are two(!) US cups. Their names might be

• UsCustomaryCup
• UsLegalCup

Would a PR for MetricCup be accepted?

[angularsen]

Absolutely :-) sounds good.

[neutmute]

#131 submitted