WooCommerce - Show stock shortcode

// usage: Only [product_stock id="1592"] available!
// code goes in functions.php for your child theme
add_shortcode('product_stock', 'product_stock');
function product_stock( $atts ) {
  if ( ! $atts['id'] ) {
    return '';
  }
  $product = get_product($atts['id']);
  return (int) $product->get_stock_quantity(); // for WC 3.x onwards
}