website: Fix theme on all pages but index.html

Author: luhenry

website/_config.yml

@@ -32,6 +32,12 @@ callouts:
 
 nav_sort: order
 
+defaults:
+  - scope:
+      path: ""
+    values:
+      layout: "default"
+
 back_to_top: true
 back_to_top_text: Back to top