add_filter( 'genesis_markup_content_close', 'insert_html_after_content_markup', 10, 2 );
/**
* Appends HTML to the closing markup for .content.
*
* @param string $close_html HTML tag being processed by the API.
* @param array $args Array with markup arguments.
*
* @return string
*/
function insert_html_after_content_markup( $close_html, $args ) {
if ( $close_html ) {
$additional_html = '<div>New HTML</div>';
$close_html = $close_html . $additional_html;
}
return $close_html;
}