doc(topology/algebra/filter_basis): modify doc of `add_group_filter_basis_of_comm` (#16597)
doc(topology/algebra/filter_basis): modify doc of `add_group_filter_basis_of_comm` (#16597)

Added the `additive` adjective to the doc for the @additive variation `add_group_filter_basis_of_comm` of `group_filter_basis_of_comm`



Co-authored-by: Kyle Miller <04892e540c93233cb5dfa2674fa5218f82feced5@gmail.com>

leanprover-community/mathlib,leanprover-community/mathlib