OOJSPlus: 1 message lacks documentation in qqq.json

[supertassu]

Hi, the following error is showing up on OOJSPlus libraryupgrader runs (e.g. #1280853):

$ /usr/bin/npm test
--- stdout ---

> test
> grunt test

Running "eslint:all" (eslint) task

Running "banana:all" (banana) task
>> 1 message lacks documentation in qqq.json.
>> Message "oojsplus-data-grid-filter-close" lacks documentation in qqq.json.
Warning: Task "banana:all" failed. Use --force to continue.

Aborted due to warnings.

--- end ---

Could you please add documentation for the missing message key?