docs(README.md): add newline for markdown-extended

Author: tomchentw

README.md

@@ -18,6 +18,7 @@ Usage
 Include the **new** universal analytics script in your html as usual, but remove `ga('send', 'pageview');`
 
 ## Enable the ga module
+
 ```js
 angular.module('yourModule', ['ga'])
 ```
@@ -42,22 +43,26 @@ You can skip the enclosing array '[]' if you start with the single-quote charact
 Of course, you can use angular expressions, as this is evaluated.
 
 Both samples are equivalent to calling `ga('send', 'event', 'player', 'play', video.id)` on the `click` event:
+
 ```html
 <a href="#" ga="'send', 'event', 'player', 'play', video.id"></a>
 <a href="#" ga="['send', 'event', 'player', 'play', video.id]"></a>
 ```
 
 You can call `ga` several times by passing an array of arrays:
+
 ```html
 <a href="#" ga="[['set', 'metric1', 10], ['send', 'event', 'player', 'play', video.id]]"></a>
 ```
 
-You can change the event by providing `ga-on` attribute
+You can change the event by providing `ga-on` attribute:
+
 ```html
 <input type="text" ga="'send', 'event', 'focus'" ga-on="focus" />
 ```
 
-By using `ga-on="init"` you can call `ga` as soon as the html is parsed
+By using `ga-on="init"` you can call `ga` as soon as the html is parsed:
+
 ```html
 <div ga="'send', 'pageview', {title: 'Hello world!'}" ga-on="init" />
 ```
@@ -66,6 +71,7 @@ By using `ga-on="init"` you can call `ga` as soon as the html is parsed
 
 If `ga` attribute is empty, the event is guesses from the context. Following examples
 are equivalent:
+
 ```html
 <div ga>LABEL</div>
 <div ga="'send', 'event', 'button', 'click', 'LABEL'">LABEL</div>