add the media css to customizer

docs/customize.html

@@ -143,6 +143,7 @@
               </div><!-- /span -->
               <div class="span3">
                 <h3>Miscellaneous</h3>
+                <label class="checkbox"><input checked="checked" type="checkbox" value="media.less"> Media object</label>
                 <label class="checkbox"><input checked="checked" type="checkbox" value="wells.less"> Wells</label>
                 <label class="checkbox"><input checked="checked" type="checkbox" value="close.less"> Close icon</label>
                 <label class="checkbox"><input checked="checked" type="checkbox" value="utilities.less"> Utilities</label>

docs/templates/pages/customize.mustache

@@ -72,6 +72,7 @@
               </div><!-- /span -->
               <div class="span3">
                 <h3>{{_i}}Miscellaneous{{/i}}</h3>
+                <label class="checkbox"><input checked="checked" type="checkbox" value="media.less"> {{_i}}Media object{{/i}}</label>
                 <label class="checkbox"><input checked="checked" type="checkbox" value="wells.less"> {{_i}}Wells{{/i}}</label>
                 <label class="checkbox"><input checked="checked" type="checkbox" value="close.less"> {{_i}}Close icon{{/i}}</label>
                 <label class="checkbox"><input checked="checked" type="checkbox" value="utilities.less"> {{_i}}Utilities{{/i}}</label>