title: Add extra fields for each menu item
body: <p>I am making a theme. There I want to add extra fields for each menu items ( <em>Appearance > Menus</em> and i.e). In the picture below I want to add some extra form fields ( like radio button, textarea and etc. ) under the field "Description":</p>
  
  <p><img src="https://i.stack.imgur.com/PYjiY.jpg" alt="menu item wordpress"></p>
  
  <p>Is there any way or tutorial about how can I do this?</p>