[Docs] add note about requiring `babel-preset-airbnb` and `airbnb-browser-shims`.
[Docs] add note about requiring `babel-preset-airbnb` and `airbnb-browser-shims`.

Fixes #1544.
airbnb/javascript,cloudability/javascript-style-guide,bl00mber/javascript,ljharb/javascript,getjll/JavaScript-Style-Guide