/**
 * Implements hook_node_view().
 */
function {{ machine_name }}_node_view($node, $view_mode, $langcode) {
  $node->content['my_additional_field'] = array(
    '#markup' => $additional_field,
    '#weight' => 10,
    '#theme' => 'mymodule_my_additional_field',
  );
}
