Approval.

themator/en/backend.json

@@ -214,6 +214,8 @@
         "object_text_original_md": "Original text from museum-digital\t",
         "md_object_either_from_md": "Either you link an object from museum-digital ...",
         "md_object_local_object": "Or you enter an object, which is not present in museum-digital ...",
-        "image_uploader": "Image uploader"
+        "image_uploader": "Image uploader",
+        "username_too_short": "Username must be at least 5 characters long",
+        "password_too_short": "A password needs to be at least 8 characters long"
     }
 }