Add outdated version warning

Author: danyeaw

mkdocs.yml

@@ -2,6 +2,7 @@ site_name: PyScript
 
 theme:
     name: material
+    custom_dir: overrides
 
     logo: assets/images/pyscript-black.svg
 

overrides/main.html

@@ -0,0 +1,8 @@
+{% extends "base.html" %}
+
+{% block outdated %}
+  You're not viewing the latest version.
+  <a href="{{ config.site_url or '../' }}"> 
+    <strong>Click here to go to latest.</strong>
+  </a>
+{% endblock %}