d8_code_test.module

<?php

/**
 * @file
 * Simple math form using the Form API.
 */

use Drupal\Core\Routing\RouteMatchInterface;

/**
 * Implements hook_help().
 */
function d8_code_test_help($route_name, RouteMatchInterface $route_match) {
  switch ($route_name) {
    case 'help.page.d8_code_test':
      $output = '';
      $output .= '<h3>' . t('About') . '</h3>';
      $output .= '<p>' . t('The D8 Code Test module allows a user to easily see the sum of two numbers by entering them into a form.') . '</p>';
      $output .= '<h3>' . t('Uses') . '</h3>';
      $output .= '<dl>';
      $output .= '<dt>' . t('Getting the total of two numbers') . '</dt>';
      $output .= '<dd>' . t('Users can enter two numbers on the <a href=":d8codetest">D8 Code Test</a> page and see a preview of the result in realtime before submitting. Submitting the form will result in a message being displayed that contains the two values and their sum.', array(':d8codetest' => \Drupal::url('d8_code_test.math_form'))) . '</dd>';
      $output .= '</dl>';
      return $output;
  }
}