feat(dashboard): show admin hints and add the hints admin page

public/i18n/en.json

@@ -284,7 +284,8 @@
       "MENU": "View as",
       "BADGE": "Viewing as {{role}}",
       "ERROR": "The role could not be switched."
-    }
+    },
+    "ADMIN_HINTS": "Hints"
   },
   "BACKLOG": {
     "TITLE": "My backlog",
@@ -545,5 +546,39 @@
       "YES": "Yes",
       "NO": "No"
     }
+  },
+  "HINT": {
+    "CLOSE": "Close",
+    "DO_NOT_SHOW_AGAIN": "Do not show again",
+    "OK": "OK",
+    "SAVE_FAILED": "The hint could not be saved."
+  },
+  "ADMIN_HINTS": {
+    "NEW": "New hint",
+    "TEXT_EN": "Text (English)",
+    "TEXT_DE": "Text (German, optional)",
+    "TEXT_HELP": "Plain text, max 500 characters. Without a German text, German users see the English one.",
+    "KIND": "Type",
+    "KIND_DISMISS": "Dismiss: closes after 30 s or with X",
+    "KIND_ACCEPT": "Accept: stays until the user clicks OK",
+    "STARTS_AT": "Start",
+    "ENDS_AT": "End",
+    "PREVIEW": "Preview",
+    "CREATE": "Publish",
+    "CREATED": "Hint published.",
+    "INVALID": "The end must be after the start and in the future.",
+    "ERROR": "The action failed.",
+    "LIST": "All hints",
+    "EMPTY": "No hints yet.",
+    "LOAD_ERROR": "The hints could not be loaded.",
+    "NO_ACCESS": "Only admins can open this page.",
+    "END": "End",
+    "ENDED": "Hint ended.",
+    "STATUS_PLANNED": "Planned",
+    "STATUS_ACTIVE": "Active",
+    "STATUS_ENDED": "Ended",
+    "RANGE": "{{start}} to {{end}}",
+    "DONE_COUNT_one": "Closed for good by {{count}} user",
+    "DONE_COUNT_other": "Closed for good by {{count}} users"
   }
 }