Add text to back button on timetable raster page

aleksis/apps/lesrooster/frontend/components/timetable_management/TimetableManagement.vue

@@ -511,7 +511,7 @@ export default defineComponent({
     <v-row>
       <v-col cols="12" lg="8" xl="9">
         <div class="d-flex justify-space-between flex-wrap align-center">
-          <secondary-action-button i18n-key="IDK, ggf back??" />
+          <secondary-action-button i18n-key="lesrooster.timetable_management.back" />
 
           <v-spacer />
 

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

@@ -61,7 +61,8 @@
     "timetable_management": {
       "menu_title": "Timetable Management",
       "for_group": "Timetable management for group {group}",
-      "timetable_for": "Timetable for {name}"
+      "timetable_for": "Timetable for {name}",
+      "back": "Back to overview"
     }
   },
   "actions": {