Rename datasets/coco_karpathy_val.json to datasets/coco/coco_karpathy_val.json

Delete datasets/coco/readme.md

Rename datasets/coco_karpathy_train.json to datasets/coco/coco_karpathy_train.json

Rename datasets/coco_karpathy_test.json to datasets/coco/coco_karpathy_test.json

Create datasets/coco/readme.md