Minor improvement to grammer in README
Minor improvement to grammer in README

hachi8833/goby,goby-lang/goby,goby-lang/goby,goby-lang/goby,hachi8833/goby,Maxwell-Alexius/goby,hachi8833/goby,st0012/Rooby,Maxwell-Alexius/goby,st0012/Rooby,Maxwell-Alexius/goby