https://www.youtube.com/watch?v=Ke90Tje7VS0&t=1274s
Setup
npm i -g create-react-app
cd 1 create-react-app react-app cd react-app npm start
remove everything inside src keep index.js as in git repo.
cd 2 create-react-app counter-app cd counter-app npm i bootstrap@4.1.1 npm start