How to add Custom Testimonial Code and Shortcode

Function.php

add_filter( 'widget_tag_cloud_args', 'twentysixteen_widget_tag_cloud_args' );

add_action( 'init', 'create_post_type' );function create_post_type() {  register_post_type( 'testimonial',    array(      'labels' => array(        'name' => __( 'Testimonial' ),        'singular_name' => __( 'testimonial' )      ),      'public' => true,      'has_archive' => true,    )  );}

CUSTOMTEMPLATE.php

<div class="carousel-inner">

       <?php

$args = array( 'posts_per_page' => -1, 'post_type' => 'testimonial' );

$i=0;

$myposts = get_posts( $args );

foreach ( $myposts as $post ) : setup_postdata( $post ); ?>

         <!-- Quote 1 -->

         <div class="item <?php if($i==0) { ?> active <?php } else { } ?>">

           <div class="col-sm-12 block-quote">

<?php the_content();?>

  <small><?php the_author(); on ?></small>

           </div>

         </div>

         <?php

    $i++;

    endforeach;

wp_reset_postdata();?>