wp quicktags for bootstrap

// add more buttons to the html editor
// https://codex.wordpress.org/Quicktags_API
function appthemes_add_quicktags() {
    if (wp_script_is('quicktags')){
?>
    <script type="text/javascript">
     QTags.addButton( 'bootstrap-container', 'Bootstrap Container','<div class="container">','</div>','<div>');
     QTags.addButton( 'bootstrap-row', 'Bootstrap Row','<div class="row">','</div>','<div>');

     for(var i= 1;i<=12;i++){
     	QTags.addButton( 'bt-col-md-'+i+'', 'bootstrap col md '+i+'','<div class="col-md-'+i+'">','</div>','<div>');
     }
     for(var i= 1;i<=12;i++){
     	QTags.addButton( 'bt-col-lg-'+i+'', 'bootstrap col lg '+i+'','<div class="col-lg-'+i+'">','</div>','<div>');
     }
     for(var i= 1;i<=12;i++){
     	QTags.addButton( 'bt-col-sm-'+i+'', 'Bootstrap col sm '+i+'','<div class="col-sm-'+i+'">','</div>','<div>');
     }

    </script>
<?php
    }
}
add_action( 'admin_print_footer_scripts', 'appthemes_add_quicktags' );

add_action('wp_head','bootstrap_css_func');
function bootstrap_css_func(){
	?>
	<link rel="stylesheet" href="//stackpath.bootstrapcdn.com/bootstrap/4.1.1/css/bootstrap.min.css">
	<?php
}