Add translations for timetable_management

aleksis/apps/lesrooster/frontend/messages/en.json

@@ -41,6 +41,10 @@
     },
     "lesson_raster": {
       "menu_title": "Lesson Raster"
+    },
+    "timetable_management": {
+      "menu_title": "Timetable Management",
+      "for_group": "Timetable management for group {group}"
     }
   },
   "actions":{