title: Replace Woocommerce product stock status with a custom field value
body: <p>Does anybody know some example filter to fill the stock status text with value from custom field?</p>
  
  <p>DB:</p>
  
  <pre><code>Product 1, stock_status = in-stock, stock_status_custom = '5 days'
  Product 2, stock_status = in-stock, stock_status_custom = '10 days'
  </code></pre>
  
  <p>CODE:</p>
  
  <pre><code>function customGetStockTextForProduct($productId){
    return get_field('stock_status_custom', $productId);
  }
  add_filter('customGetStockTextForProduct', 'customGetStockTextForProduct');
  </code></pre>