feat: Modular Arithmetic Optimization

[0xJepsen]

I think there are two modular arithmetic optimizations that would be good to add to the field.rs component.

• [x] #17
• [x] #18

While they each have there distinct applications and performance improvements, since this is a learning resource, i believe we should at some point add both of them and well document each.

There is a pretty good resource on both these algorithms with slides from risc0 here

[0xJepsen]

@lonerapier Would this be something you are interested in?

[lonerapier]

Yup @0xJepsen, will start on this

[0xJepsen]

Yup @0xJepsen, will start on this

There is an example of the montgomery optimization here: https://github.com/Plonky3/Plonky3/blob/main/baby-bear/src/baby_bear.rs, it does depend on the field size.