Shortcode para Botão

button_shortcode.php

<?php
function shortcode_btn($atts)
{
    $atts = shortcode_atts(array('url' => 'javascript:;', 'target' => '_top', 'name' => NULL), $atts);

    $url = $atts['url'];
    $target = $atts['target'];
    $name = (is_null($atts['name'])) ? $url : $atts['name'];

    return "<a href='" . $url . "' target='" . $target . "' class='btn btn-alt' >" . $name . "</a>";

}

add_shortcode('btn', 'shortcode_btn');