Adding the React-Router library

Now that we have our sample application up and running, let's add React-Router library as a dependency using npm:

npm install --save react-router-dom

This command will download and add react-router-dom to the /node_modules directory. The package.json file now includes this as a dependency:

"dependencies": {
 "react": "^16.4.0",
 "react-dom": "^16.4.0",
 "react-router-dom": "^4.3.0",
 "react-scripts": "1.1.4"
}