Remove some of the possible demos since those sites are either boring or not up enough.

public/blockstart/demos/index.html

@@ -57,14 +57,11 @@
       <shape><a href="todoist.html">Todoist</a></shape>
       <shape><a href="square.html">Square</a></shape>
       <shape><a href="earlybird.html">Earlybird</a></shape>
-      <shape><a href="pandadoc.html">Pandadoc</a></shape>
       <shape><a href="vimeo.html">Vimeo</a></shape>
       <shape><a href="wordstream.html">Wordstream</a></shape>
       <shape><a href="breadcrumbs.html">Breadcrumbs</a></shape>
-      <shape><a href="vidyard.html">Vidyard</a></shape>
       <shape><a href="snapchat.html">Snapchat</a></shape>
       <shape><a href="patreon.html">Patreon</a></shape>
-      <shape><a href="shopify.html">Shopify</a></shape>
       <shape><a href="slack.html">Slack</a></shape>
       <shape><a href="zoom.html">Zoom</a></shape>
     </grid>