New translations entities.php (Icelandic)

Author: ssddanbrown

lang/is/entities.php

@@ -268,6 +268,7 @@
     'pages_md_insert_drawing' => 'Setja inn teikningu',
     'pages_md_show_preview' => 'Sýna forskoðun',
     'pages_md_sync_scroll' => 'Sync preview scroll',
+    'pages_md_plain_editor' => 'Plaintext editor',
     'pages_drawing_unsaved' => 'Unsaved Drawing Found',
     'pages_drawing_unsaved_confirm' => 'Unsaved drawing data was found from a previous failed drawing save attempt. Would you like to restore and continue editing this unsaved drawing?',
     'pages_not_in_chapter' => 'Síðan tilheyrir engum kafla',