Merge pull request #1318 from apollographql/sb/add-sandbox-video

Add Sandbox video to docs

Author: Stephen Barlow

studio-docs/source/explorer/sandbox.mdx

@@ -24,7 +24,11 @@ Sandbox automatically attempts to connect to a GraphQL server running at `http:/
 
 <img class="screenshot" src="../img/sandbox-url.jpg" alt="Sandbox URL field" width="300" />
 
->To try out Sandbox with an example GraphQL API, you can set its URL to `https://swapi-graphql.netlify.app/.netlify/functions/index`.
+> To try out Sandbox with an example GraphQL API, you can set its URL to `https://swapi-graphql.netlify.app/.netlify/functions/index`.
+
+## Overview video
+
+<iframe width="560" height="315" src="https://www.youtube.com/embed/0jzqqHZU00Q" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 
 ## Publishing schemas from Sandbox