add_filter( 'woocommerce_product_tabs', 'bbloomer_add_product_tab', 9999 );
   
function bbloomer_add_product_tab( $tabs ) {
   $tabs['docs'] = array(
      'title' => __( 'Docs', 'woocommerce' ), // TAB TITLE
      'priority' => 50, // TAB SORTING (DESC 10, ADD INFO 20, REVIEWS 30)
      'callback' => 'bbloomer_docs_product_tab_content', // TAB CONTENT CALLBACK
   );
   return $tabs;
}
 
function bbloomer_docs_product_tab_content() {
   global $product;
   echo 'Whatever content for ' . $product->get_name();
}