Restructure train/: nest shards into chunk subdirs (batch 97/98)

Restructure train/: nest shards into chunk subdirs (batch 37/98)

Restructure train/: nest shards into chunk subdirs (batch 36/98)

Restructure train/: nest shards into chunk subdirs (batch 35/98)

Restructure train/: nest shards into chunk subdirs (batch 34/98)

Restructure train/: nest shards into chunk subdirs (batch 33/98)

Restructure train/: nest shards into chunk subdirs (batch 32/98)