WP Hero Img

add_action( 'init', 'woa_add_hero_image_init' );
function woa_add_hero_image_init () {
   add_action( 'storefront_before_content', 'woa_add_hero_image', 5 );
}
function woa_add_hero_image() {
   if ( is_front_page() ) :
      ?>
         <div id="hero-image">
             <a href="http://change_me_to_your_url"><img src="/wp-content/uploads/imageurl.jpg" width="100%"></a>
         </div>
      <?php
   endif;
}