Issue #3253193 by adamzimmermann: Improve Admin form with examples

    $form['description'] = [

      '#type' => 'markup',

      '#markup' => $this->t('<p>Noindex is configured by using path patterns or URI patterns, optionally utilizing regular expressions to match pages.</p>'),

      '#markup' => $this->t('

        <p">Noindex is configured by using path patterns, URI patterns, or regular expressions to match pages.</p>

        <p>When using regular expressions include <code>#</code> as a delimiter (e.g. <code>#^/node/[0-9]+#</code>).

      '),

    ];

    $form['route_patterns'] = [

      '#type' => 'textarea',

      '#title' => $this->t('Route patterns'),

      '#description' => $this->t('A list of internal Drupal routes or regular expression patterns to match, one per line. Use # as the regex delimiter.'),

      '#description' => $this->t('A list of internal Drupal routes (e.g. <code>/node/123</code>) or regular expression patterns to match, one per line.'),

      '#default_value' => $config->get('route_patterns'),

    ];

    $form['uri_patterns'] = [

      '#type' => 'textarea',

      '#title' => $this->t('Request URI patterns'),

      '#description' => $this->t('A list of external request URI paths or regular expression patterns to match. Use # as the regex delimiter.'),

      '#description' => $this->t('A list of external request URI paths (e.g. <code>/example/path</code>) or regular expression patterns to match.'),

      '#default_value' => $config->get('uri_patterns'),

    ];