generate polynomials from difference sequences

[4meta5]

The general term of the sequence whose difference table has its 0th diagonal equal to c_0,c_1,...,c_p,0,0,0,.., where c_p != 0 is a polynomial in n of degree p satisfying h_n = c_0 (n choose 0) + c_1 (n choose 1) + ... + c_p * (n choose p)

• [x] difference sequence impl
• [x] generate polynomials from difference sequences
• [x] add ability to compute partial sums

An interesting observation is that we are NOT recognizing polynomials. We are generating them. They are uniquely determined by the difference sequence.

[4meta5]

add docs to readme and itll be mergeable