Super basic shortcode with stylesheet enqueued globally

shortcode.php

<?php
/*
 * Example Shortcode and Globally Enqueued Stylesheet
 *
 */

// Our Shortcode function
function hiroy_shortcode( $content = null ) {
    // do something to $content
 	$content = '<h2>Hi Roy!</h2>';
    // always return
    return $content;
}
// Our Shortcode Action
add_shortcode( 'hiroy', 'hiroy_shortcode' );

// Enqueue the Stylesheet Globally
function hiroy_enqueue_scripts() {
    wp_enqueue_style( 'hiroy-css', 'hiroy.css', 'parent-stylesheet', '1.0', all ); 
}
// Enqueue Stylesheet Action
add_action( 'wp_enqueue_scripts', 'hiroy_enqueue_scripts' );