MigrateHooks.php

<?php

namespace Drupal\migrate\Hook;

use Drupal\Core\Routing\RouteMatchInterface;
use Drupal\Core\Hook\Attribute\Hook;

/**
 * Hook implementations for migrate.
 */
class MigrateHooks {
    
    /**
     * Implements hook_help().
     */
    public function help($route_name, RouteMatchInterface $route_match) {
        switch ($route_name) {
            case 'help.page.migrate':
                $output = '<h2>' . t('About') . '</h2>';
                $output .= '<p>';
                $output .= t('The Migrate module provides a framework for migrating data, usually from an external source into your site. It does not provide a user interface. For more information, see the <a href=":migrate">online documentation for the Migrate module</a>.', [
                    ':migrate' => 'https://www.drupal.org/documentation/modules/migrate',
                ]);
                $output .= '</p>';
                return $output;
        }
    }

}