Added default language pack (en-gb)

admin/design/theme.php

@@ -0,0 +1,23 @@
+<?php
+// Heading
+$_['heading_title']     = 'Theme Editor';
+
+// Text
+$_['text_success']      = 'Success: You have modified themes!';
+$_['text_edit']         = 'Edit Theme';
+$_['text_store']        = 'Choose your store';
+$_['text_template']     = 'Choose a template';
+$_['text_default']      = 'Default';
+$_['text_history']      = 'Theme History';
+$_['text_twig']         = 'The theme editor uses the template language Twig. You can read about <a href="http://twig.sensiolabs.org/documentation" target="_blank" class="alert-link">Twig syntax here</a>.';
+
+// Column
+$_['column_store']      = 'Store';
+$_['column_route']      = 'Route';
+$_['column_theme']      = 'Theme';
+$_['column_date_added'] = 'Date Added';
+$_['column_action']     = 'Action';
+
+// Error
+$_['error_permission']  = 'Warning: You do not have permission to modify the theme editor!';
+$_['error_twig']        = 'Warning: You can only save .twig files!';