gist-shortcode.php

// github gist Shortcode Usage: [gist id="" file=""]
function gist_shortcode( $atts ) {
   extract(shortcode_atts(array(
	   'id' => '',
	   'file' => ''
   ), $atts));
   return '<script src="https://gist.github.com/'.$id.'.js?file='.$file.'"></script>';
}
add_shortcode('gist', 'gist_shortcode');