title: Woocommerce Custom Field on Custom Order Details Page
body: <p>Looking over the docs, there does not appear to be a clear way to display a custom field on the customer's order details page. I have no problem getting my custom fields to display on the admin order details or the customer's email. </p>
  
  <p>The only way I can see that it can be done is if by copying over the "woocommerce/order/order-details.php" in the theme's folder. This is undesirable as it requires me to have a lingering template file that may or may not need to be updated if woo developers change the original.</p>
  
  <p>Is there a filter that can allow me to add the custom field to the customer's order details page without relying on a template?</p>
  
  <p>Just to clarify, the page I am looking to add this is when the user completes the order (their receipt page). </p>
  
  <p>Many thanks!</p>