Add file extensions back to non-helper _includes

_includes/scripts.html

@@ -0,0 +1,6 @@
+<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
+<script>window.jQuery || document.write('<script src="{{ base_path }}/assets/js/vendor/jquery-1.9.1.min.js"><\/script>')</script>
+<script src="{{ base_path }}/assets/js/main.min.js"></script>
+
+{% include analytics.html %}
+{% include comments.html %}