Buttons: Adding reset demo

Author: sfrisk

demos/buttons.html

@@ -23,6 +23,7 @@ <h2>Button tag</h2>
 	<button class="ui-button--default" type="submit">Button</button>
 	<input class="ui-button--default" type="button" value="Input">
 	<input class="ui-button--default" type="submit" value="Submit">
+	<input class="ui-button--default" type="reset" value="Reset">
 </form>
 
 <h2>Options</h2>