Add header for new plugin localization template

plugins/attachment_reminder/localization/en_US.inc

@@ -1,5 +1,21 @@
 <?php
 
+/*
+ +-----------------------------------------------------------------------+
+ | plugins/attachment_reminder/localization/<lang>.inc                   |
+ |                                                                       |
+ | Localization file of the Roundcube Webmail Archive plugin             |
+ | Copyright (C) 2013, The Roundcube Dev Team                            |
+ |                                                                       |
+ | Licensed under the GNU General Public License version 3 or            |
+ | any later version with exceptions for skins & plugins.                |
+ | See the README file for a full license statement.                     |
+ |                                                                       |
+ +-----------------------------------------------------------------------+
+
+ For translation see https://www.transifex.com/projects/p/roundcube-webmail/resource/plugin-attachment_reminder/
+*/
+
 $messages = array();
 $messages['forgotattachment'] = "Did you forget to attach a file?";
 $messages['reminderoption'] = "Remind about forgotten attachments";