boton_02.php

<?php
/**
 * Plugin Name: Boton
 * Description: Un ejemplo de shortcode
 */
if ( ! defined( 'ABSPATH' ) ) exit;

/**
* Crea shortcode [boton]
* [boton url="" color="#ff6c00"]texto[/boton]
*/
function boton_shortcode( $atts, $content = null ) {

	$boton_atts = shortcode_atts( array(

		'url' => '',
		'color' => '#ff6c00',

	), $atts );

	$boton = '<a style="color:'. esc_attr( $boton_atts['color'] ) .';" href="'. esc_url( $boton_atts['url'] ) .'">';
		$boton .= $content;
	$boton .= '</a>';

	return $boton;

}

add_shortcode( 'boton', 'boton_shortcode' );