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

Restructure train/: nest shards into chunk subdirs (batch 86/98)

Restructure train/: nest shards into chunk subdirs (batch 85/98)

Restructure train/: nest shards into chunk subdirs (batch 84/98)

Restructure train/: nest shards into chunk subdirs (batch 83/98)

Restructure train/: nest shards into chunk subdirs (batch 82/98)

Restructure train/: nest shards into chunk subdirs (batch 81/98)