Clarification about clientOptions and using JUI in AR form

I accidentally made this pull request in the read-only JUI repo, so I'm doing it again here.

extensions/jui/README.md

@@ -6,7 +6,17 @@ and makes using JQuery UI widgets in Yii applications extremely easy. For exampl
 single line of code in a view file would render a JQuery UI DatePicker widget:
 
 ```php
-<?= yii\jui\DatePicker::widget(['name' => 'start']) ?>
+<?= yii\jui\DatePicker::widget(['name' => 'attributeName']) ?>
+```
+
+Configuring the Jquery UI options should be done using the clientOptions attribute:
+```php
+<?= yii\jui\DatePicker::widget(['name' => 'attributeName', 'clientOptions' => ['dateFormat' => 'yy-mm-dd']]) ?>
+```
+
+If you want to use the JUI widget in an ActiveRecord form, it can be done like this:
+```php
+<?= $form->field($model,'attributeName')->widget(DatePicker::className(),['clientOptions' => ['dateFormat' => 'yy-mm-dd']]) ?>
 ```