Add numeric fused head dataset
Adding the [NFH: Numeric Fused Head](https://nlp.biu.ac.il/~lazary/fh/) dataset.

Everything looks sensible and I've included both the identification and resolution tasks. I haven't personally used this dataset in my research so am unable to specify what the default configuration / supervised keys should be.

I've filled out the basic info on the model card to the best of my knowledge but it's a little tricky to understand exactly what the fields represent.

Dataset author: @yanaiela 