update isomorphic problem.md
update isomorphic problem.md

workshopper/learnyoureact,tako-black/learnyoureact,marocchino/learnyoureact,Mavmeister/learnyoureact,hvp/learnyoureact,kohei-takata/learnyoureact,aksharpatel47/learnyoureact,timguoqk/learnyoureact,vbdoug/learnyoureact,thebuilder/learnyoureact