admin(README.md): add @TwoFX to the maintainers list (#6985)
admin(README.md): add @TwoFX to the maintainers list (#6985)




Co-authored-by: Scott Morrison <63f04b4d96235eb042cc46d94f14d241d2a26722@gmail.com>
Co-authored-by: Markus Himmel <300a2d193222dd0c23d880e16d727d352b404a01@himmel-villmar.de>

leanprover-community/mathlib,leanprover-community/mathlib