Integrate WooCommerce with a Custom Theme, Adding Woo Supports

function si_add_woocommerce_support() {
    add_theme_support( 'woocommerce' );
    add_theme_support( 'wc-product-gallery-zoom' );
    add_theme_support( 'wc-product-gallery-lightbox' );
    add_theme_support( 'wc-product-gallery-slider' );
} 
add_action( 'after_setup_theme', 'si_add_woocommerce_support' );