Librarian Bot: Add language metadata for dataset (#2)

- Librarian Bot: Add language metadata for dataset (7cfc23af90f761de3d1e140f16b275bbb6c8b559)


Co-authored-by: Librarian Bot (Bot) <[email protected]>

README.md

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