Convert Webparts to Functional Components (React Hooks)

I was asked recently to convert some modern webparts to use react hooks (refactor as functional components).  I struggled to find a simple tutorial, so I put one together to help anyone who has the same requirement, it uses v1.11

tutorial video here: https://www.youtube.com/watch?v=BFgGFV9Rj44&t=177s

source code here: https://github.com/Yorcloud/spfx-react-hooks-demo