add typescript to existing react project code example

Example 1: npx react typescript

npx create-react-app my-app --template typescript

Example 2: add typescript in create react app

npm install --save typescript @types/node @types/react @types/react-dom @types/jest
# or
yarn add typescript @types/node @types/react @types/react-dom @types/jest

Example 3: yarn create react app typescript

npx create-react-app my-app --template typescript
# or
yarn create react-app my-app --template typescriptCopy