add_action( 'init', 'theme_menus' );
function theme_menus() {
register_nav_menus( array(
'header-menu' => __( 'Header menu', 'twentysixteen' ),
'footer-menu' => __( 'Footer menu', 'twentysixteen' ),
));
}


add_theme_support( 'post-thumbnails' );
set_post_thumbnail_size( 'anasayfa', 500 , 500, true);