docs(README): add cli flags (#1632)

Author: bhavya9107

README.md

@@ -43,6 +43,7 @@ The easiest way to use it is with the CLI. In the directory where your
 ```console
 node_modules/.bin/webpack-dev-server
 ```
+_**Note**: Many CLI options are available with `webpack-dev-server`. Explore this [link](https://webpack.js.org/configuration/dev-server/)._
 
 ### With NPM Scripts