[Ink] Update README to include Swift examples
[Ink] Update README to include Swift examples

Reviewers: randallli, #mdc_ios_owners, featherless

Reviewed By: randallli, #mdc_ios_owners, featherless

Subscribers: featherless

Projects: #material_components_ios

Differential Revision: http://codereview.cc/D676

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