Add link to codepen

readme.md

@@ -16,7 +16,7 @@ npm install [email protected] --save
 
 Then make sure you are using postcss-import and call Axis at the top of your css:
 
-```
+```css
 @import 'axis';
 
 /* Your awesome css here */
@@ -26,6 +26,10 @@ Then make sure you are using postcss-import and call Axis at the top of your css
 
 You can find [full documentation for Axis here](#).
 
+### Try it out
+
+Dive in and see how it works in the [codepen playground](http://codepen.io/dbox/pen/NdpWPM?editors=1100).
+
 ### Bloat free
 
 Since Axis is a mixin library, it actually adds zero size to your code. That's right, when you include Axis and compile it, _not a single character is added to your code_.