formatting/grammar in contributing.md
formatting/grammar in contributing.md

jonschlinkert/remarkable,marbemac/remarkable,GerHobbelt/remarkable,nikolas/remarkable,dennisleung/remarkable,poetica/remarkable,lucyking/remarkable,nikolas/remarkable,dennisleung/remarkable,lucyking/remarkable,poetica/remarkable,k88hudson/remarkable,yzhen123/remarkable,k88hudson/remarkable,GerHobbelt/remarkable,marbemac/remarkable,PKRoma/remarkable,yzhen123/remarkable