adds date input (#21)

Author: tbolt

index.html

@@ -332,6 +332,10 @@ <h3 class="demo-header">form</h3>
         <label for="favnum"> Favorite Number </label>
         <input type="number" id="favnum" name="favnum" value="" />
       </div>
+      <div class="form-example">
+        <label for="date"> Date </label>
+        <input type="date" id="date" name="date" value="" />
+      </div>
       <div class="form-example">
         <label for="surprise">
           <input type="checkbox" id="surprise" name="surprise" value="" />