Issue #3285078 by robphillips: Implements hook_help() with documentation link.

<?php

/**

 * @file

 * Integrates Choices.js plugin with entity reference autocomplete fields.

 */

use Drupal\Core\Routing\RouteMatchInterface;

use Drupal\Core\Url;

/**

 * Implements hook_help().

 */

function choices_autocomplete_help($route_name, RouteMatchInterface $route_match): string {

  $build = [];

  if ($route_name === 'help.page.choices_autocomplete') {

    $build[] = [

      '#markup' => '<h2>' . t('Documentation') . '</h2>',

    ];

    $build[] = [

      '#type' => 'link',

      '#title' => 'https://git.drupalcode.org/project/choices_autocomplete/-/blob/1.x/README.md',

      '#url' => Url::fromUri('https://git.drupalcode.org/project/choices_autocomplete/-/blob/1.x/README.md'),

    ];

  }

  return \Drupal::service('renderer')->render($build);

}