Changing url's
Url's can be changed in file sitekly/app/Config/Routes.php.
To change url from /lang to /language find lines:
$routes->get('lang/(:segment)', 'Lang::index/$1',['as' => 'lang/']);
$routes->get('lang/(:segment)/(:segment)', 'Lang::index/$1/$2',['as' => 'lang//']);
and change it to:
$routes->get('language/(:segment)', 'Lang::index/$1',['as' => 'lang/']);
$routes->get('language/(:segment)/(:segment)', 'Lang::index/$1/$2',['as' => 'lang//']);
Builder is using named routes so you don't need to change links in views.