Document manually calling `PUSH()`.

Closes #753.

docs/components.html

@@ -1259,6 +1259,13 @@ document
 {% highlight js %}
 // Only needed if you want to fire a callback
 window.addEventListener('push', myFunction);
+{% endhighlight %}
+
+        <p class="component-description">Push.js can be triggered manually by using the PUSH(options) function. When passing options, url is required, container, transition and timeout are optional. As of version 2.1.0 Ratchet has its own namespace and can also be called with RATCHET.push(options).</p>
+
+{% highlight js %}
+PUSH({url: "/signin"});
+RATCHET.push({url: "/signin"});
 {% endhighlight %}
 
       </article>