help: Close other article headings on click.

This commit adds a minor improvment in clicking
the left sidebar behaviour. So if you click on
an article heading then other opened headings will
be closed automatically. This makes the toggle
experience better.

static/js/portico/help.js

@@ -137,6 +137,9 @@ function scrollToHash(container) {
         var $next = $(e.target).next();
 
         if ($next.is("ul")) {
+            // Close other article's headings first
+            $('.sidebar ul').not($next).hide();
+            // Toggle the heading
             $next.slideToggle("fast", "swing", function () {
                 markdownPS.update();
             });