Drupal 8 Adding a Reset Button to a form

drupal-8.form.reset-button.php

<?php
/**
 * Implements template_preprocess_form().
 */
function TEMPLATE_preprocess_form(&$vars) {
  $vars['form']['actions']['reset'] = [
    '#type' => 'html_tag',
    '#tag' => 'input',
    '#attributes' => [
      'class' => 'button',
      'type' => 'reset',
      'value' => 'Reset',
    ],
  ];
}

form.php

<?php

$form['actions']['reset'] = [
  '#type' => 'html_tag',
  '#tag' => 'button',
  '#value' => t('Cancel'),
  '#attributes' => [
    'class' => ['btn', 'btn-default'],
    'type' => 'reset',
  ],
];