add plugin description page

Application/Controller/Admin/MailCheckBase.php

@@ -31,7 +31,7 @@ class MailCheckBase extends AdminController
     public function render(): string
     {
         $this->addTplParam('sListClass', MailCheckMenu::class);
-        $this->addTplParam('sMainClass', MailConfigCheck::class);
+        $this->addTplParam('sMainClass', MailInfoPage::class);
 
         return parent::render();
     }

Application/Controller/Admin/MailInfoPage.php

@@ -0,0 +1,23 @@
+<?php
+
+/**
+ * This Software is the property of Data Development and is protected
+ * by copyright law - it is NOT Freeware.
+ * Any unauthorized use of this software without a valid license
+ * is a violation of the license agreement and will be prosecuted by
+ * civil and criminal law.
+ * http://www.shopmodule.com
+ *
+ * @copyright (C) D3 Data Development (Inh. Thomas Dartsch)
+ * @author        D3 Data Development - Daniel Seifert <support@shopmodule.com>
+ * @link          http://www.oxidmodule.com
+ */
+
+namespace D3\MailConfigChecker\Application\Controller\Admin;
+
+use OxidEsales\Eshop\Application\Controller\Admin\AdminDetailsController;
+
+class MailInfoPage extends AdminDetailsController
+{
+    protected $_sThisTemplate = 'mailInfoPage.tpl';
+}