Edit User Guide: Add ESLint config for VS Code users (facebook#1482)

* Add ESLint config for VS Code users

* Update VSC ESLint note to a better solution 

Update VSC ESLint note to a better solution as discussed in Pull Request

Author: vulong23

packages/react-scripts/template/README.md

@@ -185,6 +185,18 @@ You would need to install an ESLint plugin for your editor first.
 
 ><img src="http://i.imgur.com/yVNNHJM.png" width="300">
 
+
+>**For Visual Studio Code users**
+
+>VS Code ESLint plugin automatically detects Create React App's configuration file. So you do not need to create `eslintrc.json` at the root directory, except when you want to add your own rules. In that case, you should include CRA's config by adding this line:
+
+>```js
+{
+  // ...
+  "extends": "react-app"
+}
+```
+
 Then add this block to the `package.json` file of your project:
 
 ```js