Update the Swift/Obj-C example guidance (#959)
Update the Swift/Obj-C example guidance (#959)

* Update the Swift/Obj-C example guidance.

* Update checklist.md

sigito/material-components-ios,brianjmoore/material-components-ios,randallli/material-components-ios,randallli/material-components-ios,brianjmoore/material-components-ios,material-components/material-components-ios,willlarche/material-components-ios,Eccelor/material-components-ios,Eccelor/material-components-ios,chriscox/material-components-ios,randallli/material-components-ios,willlarche/material-components-ios,Eccelor/material-components-ios,samnm/material-components-ios,material-components/material-components-ios,chriscox/material-components-ios,willlarche/material-components-ios,randallli/material-components-ios,brianjmoore/material-components-ios,sigito/material-components-ios,chriscox/material-components-ios,chriscox/material-components-ios,samnm/material-components-ios,Eccelor/material-components-ios,brianjmoore/material-components-ios,sigito/material-components-ios,samnm/material-components-ios,sigito/material-components-ios,randallli/material-components-ios,brianjmoore/material-components-ios,randallli/material-components-ios,material-components/material-components-ios,material-components/material-components-ios,sigito/material-components-ios,willlarche/material-components-ios,willlarche/material-components-ios,material-components/material-components-ios,samnm/material-components-ios,chriscox/material-components-ios,Eccelor/material-components-ios,samnm/material-components-ios