Seulkee Kang

## Done - Install the `eslint-plugin-jsx-a11y` and create `eslint-a11y.config.js` file separately from `.eslintrc.js` **Reference**: https://github.com/jsx-eslint/eslint-plugin-jsx-a11y - Add `lint-a11y` script to `package.json` and `github actions workflow` - Include file extensions, `.jsx`,...

## Done - Related to #4764 - Add file extensions, `.js`, `.ts`, `.jsx`, `.tsx`, to `lint-js` script - Fix the existing linting issues with `--fix` option, `prettier`, added rules, e.g.,...