added main example

book/1_1_trait_objects.html

@@ -350,6 +350,21 @@ one. <a href="https://github.com/async-rs/async-std">async std</a> and <a href="
         </div>
 
         
+        <!-- Livereload script (if served using the cli tool) -->
+        <script type="text/javascript">
+            var socket = new WebSocket("ws://localhost:3001");
+            socket.onmessage = function (event) {
+                if (event.data === "reload") {
+                    socket.close();
+                    location.reload(true); // force reload from server (not from cache)
+                }
+            };
+
+            window.onbeforeunload = function() {
+                socket.close();
+            }
+        </script>
+