Shortcode para mostrar gists

gistfile1.phtml

/**
 * Shortcode para mostrar gists 
 * Originally taken from https://kopepasah.com/tutorial/github-gist-shortcode-for-wordpress/
 */ 
function gist_shortcode( $atts ) {
	extract( shortcode_atts( array(
		'id' => '',
		'file' => '',
	), $atts ) );

	$gist = sprintf(
		'<script src="https://gist.github.com/%s.js%s"></script>',
		esc_attr( $id ),
		$file ? '?file=' . esc_attr( $file ) : ''
	);

	return $gist;
}
add_shortcode( 'gist', 'gist_shortcode' );