added imgs for data binding

Author: ostepane

ng-data-binding/css/own.css

@@ -1,4 +1,6 @@
 .devon.reveal  .title-with-image img {
     margin-right: 0.5em;
 }
-
+.small-img{
+    width: 300px;
+}

ng-data-binding/img/event.svg

@@ -57,6 +57,7 @@ <h2>Interpolation</h2>
             <div class="title-with-image">
                 <img class="reset" src="img/property-binding.png">
                 <h2>Property Binding</h2>
+                <img class="small-img" src="img/property.svg">
             </div>
             <pre class="width-100-percent"><code class="hljs html" data-trim data-noescape>
 &lt;ul&gt;
@@ -120,6 +121,7 @@ <h2>Property Binding</h2>
             <div class="title-with-image">
                 <img class="reset" src="img/event-binding.png">
                 <h2>Event Binding</h2>
+                <img class="small-img" src="img/event.svg">
             </div>
             <pre class="width-100-percent"><code class="hljs html" data-trim data-noescape>
 &lt;book-entry [currentBook]="books[0]"