Add Multilinear Polynomial KZG Commitments

[annamiraotoole]

• Add multikzg module which implements polynomial commitments with multilinear polynomials
• Add new documentation, add to existing kzg documentation

[Pratyush]

FWIW we have an implementation of the multilinear polynomial commitment also in poly-commit: https://github.com/arkworks-rs/poly-commit/tree/master/src/multilinear_pc

[huyuncong]

FWIW we have an implementation of the multilinear polynomial commitment also in poly-commit: https://github.com/arkworks-rs/poly-commit/tree/master/src/multilinear_pc

I think this Implementation is for Lagrange basis multilinear polynomial commitment, while ours is for Coefficient basis.

[Pratyush]

Ah I see, that's cool! If it makes sense for y'all, once your impl is done we can move it poly-commit also!