adding sharecard info (#416)

* check

* does this work?

* attempt #2 at image

docs/tutorials/viewer/viewer_quickstart.md

@@ -17,4 +17,6 @@ The viewer is built using [ThreeJS](https://threejs.org/) and packaged into a [R
 
 This pulls up a hosted web-viewer which is the fastest way to get started with visualizing your nerfactory training progress!
 
+![viewer](imgs/bulldozer.png)
+
 If you want to host the viewer locally/yourself, please proceed to "For devleopers" section.

nerfactory/viewer/app/public/index.html

@@ -24,7 +24,13 @@
       work correctly both with client-side routing and a non-root public URL.
       Learn how to configure a non-root public URL by running `npm run build`.
     -->
-    <title>Nerfviewer</title>
+    <title>Nerfactory Hub</title>
+    <meta name="description" content="At the Hub, you can visualize training,
+    interact with your NeRF, and easily create your ideal 3D video." />
+    <meta property="og:title" content="Nerfactory Hub" />
+    <meta property="og:description" content="At the Hub, you can visualize training,
+      interact with your NeRF, and easily create your ideal 3D video." />
+    <meta property="og:image" content="https://plenoptix-nerfactory.readthedocs-hosted.com/en/latest/_images/bulldozer.png" alt="Nerfactory Hub"/>
   </head>
 
   <body>