Data viewing / Batch Reconstruction utility

[haileyschoelkopf]

I need to upload a utility / sample guide on how to inspect the data ordering / extract a batch at a given timestep. This'll essentially be a cleaned up version of the memorized seq util I'm working on.

Features we want:

• Verified correct dataloader construction (verify w/ memorization)
• Tool to extract + save a single timestep's batch to a numpy file
• Take as argument a YML file from this repo
• Detach from GPT-NeoX repo fully (or preserve this utility in a separate branch of NeoX)
• Argparse to select: model, mode, some default statistics?
• Support stepping through data over all timesteps + recording a statistic

[haileyschoelkopf]

This was completed in #47 !