[Docs] improve readme

Removed ESLint 1.x config information as it's probably used by very, very few people. Restructured config section to focus on quick set-up with defaults over more time consuming individual rule selection. No need to specify the plugin configuration as it works without it so it seems to be noise?

Author: briandipalma

README.md

@@ -21,45 +21,50 @@ $ npm install eslint-plugin-react --save-dev
 
 # Configuration
 
-Add `plugins` section and specify ESLint-plugin-React as a plugin.
+Use [our preset](#recommended) to get reasonable defaults:
 
 ```json
-{
-  "plugins": [
-    "react"
+  "extends": [
+    "eslint:recommended",
+    "plugin:react/recommended"
   ]
-}
 ```
 
-You can also specify some settings that will be shared across all the plugin rules.
+You should also specify settings that will be shared across all the plugin rules.
 
 ```json5
 {
   "settings": {
     "react": {
-      "createClass": "createReactClass", // Regex for Component Factory to use, default to "createReactClass"
+      "createClass": "createReactClass", // Regex for Component Factory to use,
+                                         // default to "createReactClass"
       "pragma": "React",  // Pragma to use, default to "React"
       "version": "15.0", // React version, default to the latest React stable release
       "flowVersion": "0.53" // Flow version
     },
-    "propWrapperFunctions": [ "forbidExtraProps" ] // The names of any functions used to wrap the propTypes object, such as `forbidExtraProps`. If this isn't set, any propTypes wrapped in a function will be skipped.
+    "propWrapperFunctions": [ "forbidExtraProps" ] // The names of any functions used to wrap the
+                                                   // propTypes object, e.g. `forbidExtraProps`.
+                                                   // If this isn't set, any propTypes wrapped in
+                                                   // a function will be skipped.
   }
 }
 ```
 
-If it is not already the case you must also configure `ESLint` to support JSX.
+If you do not use a preset you will need to specify individual rules and add extra configuration.
 
-With ESLint 1.x.x:
+Add "react" to the plugins section.
 
 ```json
 {
-  "ecmaFeatures": {
-    "jsx": true
-  }
+  "plugins": [
+    "react"
+  ]
 }
 ```
 
-With ESLint 2.x.x or 3.x.x:
+Enable JSX support.
+
+With ESLint 2+
 
 ```json
 {
@@ -71,7 +76,7 @@ With ESLint 2.x.x or 3.x.x:
 }
 ```
 
-Finally, enable all of the rules that you would like to use.  Use [our preset](#recommended) to get reasonable defaults quickly, and/or choose your own:
+Enable the rules that you would like to use.
 
 ```json
   "rules": {