<body>
<div id="root"></div>
</body>
yarn add react react-dom // yarn.lock 생성
yarn add -D typescript @types/react @types/react-dom // tsconfig.json 생성
{
"compilerOptions": {
"target": "ES5",
"module": "ESNext",
"moduleResolution": "node",
"lib": ["DOM", "ESNext"],
"jsx": "react-jsx",
"noEmit": true,
"isolatedModules": true,
"esModuleInterop": true,
"strict": true,
"skipLibCheck": true,
"forceConsistentCasingInFileNames": true,
"resolveJsonModule": true
},
"include": ["src/**/*"]
}