update copysort documentation
update copysort documentation

rlugojr/dragula,sherbrow/dragula,rwillbrown/dragula,sherbrow/dragula,linearza/dragula,looker/dragula,jaw4ik/dragula,jaw4ik/dragula,luckylooke/dragon,romainbessugesmeusy/dragula,bevacqua/dragula,romainbessugesmeusy/dragula,looker/dragula,luckylooke/dragon,rlugojr/dragula,bevacqua/dragula,jimf/dragula,rwillbrown/dragula,linearza/dragula,jimf/dragula