A boilerplate for React made manually without the use of CRA.
Never use create-react-app again!

Run npm init -y

Install the following pacakges via npm or yarn to get it up and running:
Use --save-dev for all except react, react-dom and sass

• @babel/cli
• @bable/core
• @babel/preset-env
• @babel/preset-react
• babel-loader
• css-loader (if not using sass)
• eslint
• eslint-config-prettier
• eslint-plugin-jest
• husky (setup to use .jsx extensions when running commit/test)
• html-webpack-plugin
• jest
• jest-environment-jsdom
• prettier (use --save-dev and --save-exact)
• webpack
• webpack-cli
• webpack-dev-server
• react (make sure to use .jsx instead of .js for files)
• react-dom
• sass (optional)
• sass-loader (optional, needed with sass)
• @testing-library/react
• @testing-library/jest-dom

Make sure to use git init before installing husky

This will make formatting consistent across all commits and any number of collaborators.
To use TypeScript you may have to do some minor configuring and use .tsx extensions (haven't tested this yet)