Docs: popover selector option example broken

Created by: gricey432

In the docs for popover under the selector option https://getbootstrap.com/docs/4.1/components/popovers/#options it links to "an informative example" https://jsbin.com/zopod/1/edit?html,css,js,console,output however the example is broken.

"ReferenceError: $ is not defined
    at zopod.js:10:1
    at https://static.jsbin.com/js/prod/runner-4.1.4.min.js:1:13924
    at https://static.jsbin.com/js/prod/runner-4.1.4.min.js:1:10866"

Linux, Chrome