custom holder theme

docs/_includes/footer.html

@@ -59,6 +59,15 @@ SimpleJekyllSearch.init({
   noResultsText: '<li class="no-results">Sorry, there are no results for that search.</li>',
   dataSource: '/search.json'
 })
+
+Holder.addTheme('gray', {
+  background: '#0275d8',
+  foreground: 'rgba(255,255,255,.65)',
+  font: 'Helvetica',
+  fontweight: 'normal',
+  size: 16,
+  text: 'Thumbnail'
+})
 </script>
 
 {% comment %}