Document how to add linting in an editor

Author: gaearon

template/README.md

@@ -219,6 +219,30 @@ Please be advised that this is also a custom feature of Webpack.
 
 **It is not required for React** but many people enjoy it (and React Native uses a similar mechanism for images). However it may not be portable to some other environments, such as Node.js and Browserify. If you prefer to reference static assets in a more traditional way outside the module system, please let us know [in this issue](https://github.com/facebookincubator/create-react-app/issues/28), and we will consider support for this.
 
+### Display Lint Output in the Editor
+
+>Note: this feature is available with `[email protected]` and higher.
+
+Some editors, including Sublime Text and Atom, provide plugins for ESLint. You would need to install such a plugin first. Once you install and enable an ESLint plugin for your editor, make sure `package.json` of your project ends with this block:
+
+```js
+{
+  // ...
+  "eslintConfig": {
+    "extends": "./node_modules/react-scripts/config/eslint.js"
+  }
+}
+```
+
+Projects generated with `[email protected]` and higher should already have it.
+
+There are two limitations:
+
+* This only works with npm >= 3 because of [an ESLint issue](https://github.com/eslint/eslint/issues/3458).
+* You can’t delete these lines. We don’t like configuration as much as you do, and [are looking for better solutions](https://github.com/facebookincubator/create-react-app/issues/215).
+
+If you don’t need ESLint integration with your editor, you can safely delete those three lines from your `package.json`.
+
 ### Add Flow
 
 Flow typing is currently [not supported out of the box](https://github.com/facebookincubator/create-react-app/issues/72) with the default `.flowconfig` generated by Flow. If you run it, you might get errors like this:
@@ -277,6 +301,8 @@ We will consider integrating more tightly with Flow in the future so that you do
 
 ### Deploy to GitHub Pages
 
+>Note: this feature is available with `[email protected]` and higher.
+
 First, open your `package.json` and add a `homepage` field.
 It could look like this: