refs #276: Enable to select highlight.js style

WIP
choice highlight theme

lib/views/admin/customize.html

@@ -149,9 +149,16 @@
           <div class="form-group">
             <div class="col-xs-3">
               <select class="form-control" name="settingForm[customize:highlight]">
-                <option value="github">Github</option>
                 <option value="atom-one-dark">Atom One Dark</option>
                 <option value="atom-one-light">Atom One Light</option>
+                <option value="github-gist">Github Gist</option>
+                <option value="github">Github</option>
+                <option value="hybrid">Hybrid</option>
+                <option value="monokai">Monokai</option>
+                <option value="tomorrow-night">Tomorrow Night</option>
+                <option value="vs">Vs</option>
+                <option value="vs2015">Vs 2015</option>
+                <option value="xcode">Xcode</option>
               </select>
             </div>
           </div>