Add Jupyter Book Calendar (#813)

Author: jasongrout

community.md

@@ -98,7 +98,7 @@ This is a calendar of regular online events.  It might not be exhaustive.
   <iframe title="Calendar of Project Jupyter events"
           class="responsive-iframe"
           id="calendariframe"
-          src="https://calendar.google.com/calendar/embed?height=600&amp;wkst=1&amp;bgcolor=%23ffffff&amp;ctz=local&amp;src=bTNoZWs2OWRhZzczODF1bXQ4a2NqZDc1dTRAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&amp;src=ZGdwZDM2ZjQzZXQ5Z3JhYm42dGRpbjZwbWNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&amp;src=YXFwa3VpNXE3b2kzMnBrOXRjcDUzaG5zc2NAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&amp;src=cGlhaGluZWpqcjZzc3ZpOGlrbWpqb3A2cm9AZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&amp;color=%23AD1457&amp;color=%23EF6C00&amp;color=%23616161&amp;color=%23F6BF26&amp;color=%239E69AF"
+          src="https://calendar.google.com/calendar/embed?height=600&amp;wkst=1&amp;bgcolor=%23ffffff&amp;ctz=local&amp;src=bTNoZWs2OWRhZzczODF1bXQ4a2NqZDc1dTRAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&amp;src=ZGdwZDM2ZjQzZXQ5Z3JhYm42dGRpbjZwbWNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&amp;src=YXFwa3VpNXE3b2kzMnBrOXRjcDUzaG5zc2NAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&amp;src=cGlhaGluZWpqcjZzc3ZpOGlrbWpqb3A2cm9AZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&amp;src=Y184YWIxNzY1YjY1ODY3NDVkOGI3NWU5MmJkYzdjYTZlNDZjYWExMmE1ZjhkOTUwZDVmNzNmMzI2Zjk3NjE0NGQ3QGdyb3VwLmNhbGVuZGFyLmdvb2dsZS5jb20&amp;color=%23AD1457&amp;color=%23EF6C00&amp;color=%23616161&amp;color=%23F6BF26&amp;color=%239E69AF&amp;color=%23e67c73"
           width="800"
           height="600"
           style="border: 0; overflow: hidden;"></iframe>