Add video of Jack

source/lovelace/index.markdown

@@ -9,7 +9,7 @@ sharing: true
 footer: true
 ---
 
-<p class='note warning'>
+<p class='note'>
 This is an experimental feature. Configuration might change in future versions.
 </p>
 
@@ -22,6 +22,10 @@ The Lovelace UI is:
  - **Extremely extensible**. It's based on the web standard [custom elements](https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements). Don't like the built-in cards? Make your own! Custom cards are treated the same as built-in cards and are configured the same way. [Check the docs.](lovelace_custom_card.md)
  - **Making the backend faster**. With Lovelace, the backend will no longer need to maintain entities like groups for the sole purpose of showing them on the frontend.
 
+<div class='videoWrapper'>
+<iframe width="560" height="315" src="https://www.youtube.com/embed/6FX9_leiikw" frameborder="0" allowfullscreen></iframe>
+</div>
+
 ## How it works
 
 The old user interface relied solely on the state machine. This caused trouble as it meant that the state machine was now not only the source for device states, but also for user interface configuration. With Lovelace, we're taking a completely different approach. All user interface configuration will live in a seperate file, controlled by the user.