react dropdown menu
https://www.skptricks.com/2018/05/create-dropdown-using-reactjs.html
https://codepen.io/mlaursen03/pen/PqVjMm
https://scotch.io/tutorials/5-most-common-dropdown-use-cases-solved-with-react-downshift
https://github.com/react-component/dropdown
https://codedaily.io/tutorials/63/Create-a-Dropdown-in-React-that-Closes-When-the-Body-is-Clicked
https://sanusart.github.io/react-dropdown-select/
https://blog.campvanilla.com/reactjs-dropdown-menus-b6e06ae3a8fe