title: Add a custom action button in WooCommerce admin order list
body: <p>I have followed <a href="https://fernandoacosta.net/blog/2015/06/07/woocommerce-adicionar-novo-status-de-pedido/" rel="nofollow noreferrer">this instructions</a> to add a custom order status for my WooCommerce Orders.</p>
  
  <p>I can't find a way to create a custom  action button that changes the order status to my custom status from the admin order list page like this screenshot:</p>
  
  <p><a href="https://i.stack.imgur.com/qqNsL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/qqNsL.png" alt="This image shows where I want it to be."></a> </p>
  
  <p>I would like this custom action button to be shown for the orders that have a "Processing" status.</p>
  
  <p>I could not find any answer in WooCommerce documentation. </p>
  
  <p>Is there a hook to apply these buttons? <br>
  How can I add it in the <code>function.php</code>?</p>
  
  <p>Thank you</p>