Fix topbar link to extensions

Author: bettio

_data/home.yml

@@ -11,8 +11,8 @@ navbar_entries:
   - title: github
     url: https://github.com/atomvm
 
-  - title: https://atomvm.org/extensions/
-    url: extensions
+  - title: extensions
+    url: https://atomvm.org/extensions/
 
   - title: forum
     url: https://erlangforums.com/c/erlang-platforms/atomvm-forum/76