docs: Update front page to display date of last update.

docs/conf.py

@@ -143,7 +143,7 @@ html_theme_path = ['.']
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.
-#html_last_updated_fmt = '%b %d, %Y'
+html_last_updated_fmt = '%d %b %Y'
 
 # If true, SmartyPants will be used to convert quotes and dashes to
 # typographically correct entities.

docs/topindex.html

 {% extends "defindex.html" %}
-{% block tables %}
+{% block body %}
+
+  <h1>Micro Python documentation</h1>
+
+  <p>
+    {{ _('Welcome! This is the documentation for Micro Python') }}
+    v{{ release|e }}{% if last_updated %}, {{ _('last updated') }} {{ last_updated|e }}{% endif %}.
+  </p>
+
   <p><strong>Documentation for Micro Python and the pyboard:</strong></p>
 
   <table class="contentstable"><tr>