Add check for 0 available brain updates

Author: trickeydan

kit/brain_board/updates.md

@@ -12,6 +12,10 @@ Once you have downloaded the file you need, refer to the documentation on [updat
 
 Each update file is a complete upgrade. Each file contains the changes of those before it. If you need to jump up multiple versions, you can do so by using the latest file.
 
+{% if site.data.kit_versions.size > 0 %}
 The following table outlines the updates which have been published.
 
 {% include updates-table.html %}
+{% else %}
+There are currently no updates available.
+{% endif %}