The schema was added before the Hindi (73b0c68) and Polish/Korean
(118e4bd) instructions landed, so languageMap and languageStepsMap
still only declared en, es, it, tr, ru, zh.
All 1,324 records carry all nine languages and the README documents
nine, but `additionalProperties` let hi/pl/ko through unvalidated and
unrequired — a record silently missing them still passed validation.
Declare all nine in `properties` and `required` for both maps.
Verified: the 1,324 records validate cleanly against the updated
schema, and a record missing hi/pl/ko is now rejected.
umutcakirai
daceea8667