mir.combinatorics: reviewers and ideas are wanted

[9il via Digitalmars-d-announce]

Hello All,

Sebastian Wilzbach (aka @greenify) starts mir.combinatorics.

Numeric functions:
- `binomial`

Ranges:
- `permutations` RoR
- `cartesianPower` RoR
- `combinations` RoR
- `combinationsRepeat` RoR

RoR - Range of Ranges

PR: https://github.com/DlangScience/mir/pull/29


Best regards,
Ilya