Issue #3276126 by eleonel: Improve help texts.

      '#required' => TRUE,

    ];

    $help = nl2br($this->t("Enter a list of allowed parameters to be retrieved, one per line. All other parameters are ignored.

    $help = nl2br($this->t("Enter a list of allowed properties to be retrieved, one per line. All other properties are ignored.

The '*' character is a wildcard. All entries are treated as a shell wildcard pattern.

Examples:

  123* matches every tag that starts with 123.

  *123 matches every tag that ends 123.

  *123* matches every tag that contains 123.

  tags matches every property name equals to tags.

  tags* matches every property name that starts with tags.

  *tags matches every property name that ends tags.

  *tags* matches every property name that contains tags.

Other shell wildcards such as ., ?, !, [] are honored for advanced users."));

    $form['allowed_contact_properties'] = [

      '#title' => $this->t('Contact Properties'),

      '#type' => 'textarea',

      '#default_value' => $this->configuration['allowed_contact_properties'] ?? '',

      '#default_value' => $this->configuration['allowed_contact_properties'] ?? 'tags',

      '#required' => TRUE,

      '#description' => $help,

    ];

    $help = nl2br($this->t("Enter a list of allowed tags to be retrieved, one per line. All other tags are ignored.

    $help = nl2br($this->t("Enter a list of allowed tags namespaces to be retrieved, one per line. All other tags are ignored.

The '*' character is a wildcard. All entries are treated as a shell wildcard pattern.

Examples:

  123* matches every tag that starts with 123.

  *123 matches every tag that ends 123.

  *123* matches every tag that contains 123.

  campaign* matches every tag that starts with the namespace campaign.

  *campaign matches every tag that ends the namespace campaign.

  *campaign* matches every tag that contains the namespace campaign.

Other shell wildcards such as ., ?, !, [] are honored for advanced users."));

Important: On Mailchimp each tag should have a '/' separating the namespace from the tag name, example 'campaign/recurring-customer'."));

    $form['allowed_contact_tags'] = [

      '#title' => $this->t('Contact Tags'),