Adding a better example of image-set (mdn#3970)

files/en-us/web/css/image-set()/index.html

@@ -34,9 +34,7 @@ <h2 id="Examples">Examples</h2>
 
 <h3 id="Using_image-set_to_provide_alternative_background-image_options">Using image-set() to provide alternative background-image options</h3>
 
-<pre class="brush: css">background-image: image-set( "cat.png" 1x,
-                             "cat-2x.png" 2x,
-                             "cat-print.png" 600dpi);</pre>
+<p>{{EmbedGHLiveSample("css-examples/images/image-set.html", '100%', 600)}}</p>
 
 <p>This example shows how to use <code><a class="css" href="https://drafts.csswg.org/css-images-4/#funcdef-image-set" id="ref-for-funcdef-image-set⑨">image-set()</a></code> to provide two alternative {{cssxref("background-image")}} options, chosen depending on the resolution needed: a normal version and a high-resolution version.</p>