Librarian Bot: Add language metadata for dataset (#1)

- Librarian Bot: Add language metadata for dataset (71e3804ac4fa0cc40bb701ded041a80d794c1b29)


Co-authored-by: Librarian Bot (Bot) <librarian-bot@users.noreply.huggingface.co>

README.md

@@ -1,4 +1,6 @@
 ---
+language:
+- ja
 dataset_info:
   features:
   - name: instruction_id