[Merged by Bors] - feat(RingTheory/PowerSeries/WellKnown): the power series of 1 / ((1 - x) ^ (d + 1)) with coefficients in a commutative ring S, where d : ℕ.

[Merged by Bors] - feat(RingTheory/PowerSeries/WellKnown): the power series of 1 / ((1 - x) ^ (d + 1)) with coefficients in a commutative ring S, where d : ℕ. #53688