hook_after_setup_theme.php

<?php

add_action( 'after_setup_theme', 'wphc_theme_setup' );

function wphc_theme_setup() {
	
	add_theme_support( 'html5', array(
		'search-form', 'comment-form', 'comment-list', 'gallery', 'caption'
	) );
	
	add_theme_support( 'post-thumbnails' );
	add_image_size( 'custom-thumb', 200, 200 );
	
	register_nav_menus( array(
		'primary' => __( 'Primary Menu',      'wphc' ),
		'footer'  => __( 'Footer Links Menu', 'wphc' ),
	) );
	
}