mathlib3

7013e5b7 - feat(category_theory/internal): commutative monoid objects (#4186)

feat(category_theory/internal): commutative monoid objects (#4186) This reprises a series of our recent PRs on monoid objects in monoidal categories, developing the same material for commutative monoid objects in braided categories. Co-authored-by: Scott Morrison <scott.morrison@gmail.com>