Project: webpack
Task (moderate): Add `import './index.css'` in `src/index.js`.
Display text `hello css` in div with CSS class `.css` in `src/index.js`.

Add `import './index.less'` in `src/index.js`.
Display text `hello less` in div with CSS class `.less` in `src/index.js`.

Add `import lessStyles from './index.module.less'` in `src/index.js`.
Display text `hello less modules` in div with CSS class referencing to variable`lessStyles.lessModules` in `src/index.js`.

Also help me update other files in this project to ensure `dev` and `build` commands won't throw errors after doing that.