Merge pull request #8791 from acmetech/3.0.0-wip

Update the code example for <select> multiple

css.html

@@ -1452,7 +1452,7 @@ For example, <code>&lt;section&gt;</code> should be wrapped as inline.
   <option>5</option>
 </select>
 
-<select multiple="multiple" class="form-control">
+<select multiple class="form-control">
   <option>1</option>
   <option>2</option>
   <option>3</option>