Bootcamp II is a wordpress theme (as well as an inside joke) designed to suit the needs of foothillschurch.com. It makes use of webpack, Babel, Sass, Tailwind, Browsersync, PostCSS, ESLint, Stylelint, Prettier and more. It is meant for that site, but if you can use it by all means go for it.
https://github.com/Myzwer/foothillschurch/blob/d75494784caf988edbcdb95afebe7becdca009e7/assets/src/js/frontend.js#L10
https://github.com/Myzwer/foothillschurch/blob/d75494784caf988edbcdb95afebe7becdca009e7/assets/src/js/frontend.js#L36
https://github.com/Myzwer/foothillschurch/blob/d75494784caf988edbcdb95afebe7becdca009e7/assets/src/js/frontend.js#L42
This shorthand is deprecated. According to their docs you should be using
.on("click", function() {})