Add kitaev_20 statistical manifold.

Add FIL 24 statistical manifold.

Add hubbard_12; fix xxz_300_z/seed_04/gt_fim.parquet

Add XXZ300Z SM

Reword README.md.

Adjust dataset card

Add description for isnnn_400.seed01 dataset.

Organize files according to https://huggingface.co/docs/datasets/main/en/repository_structure

Put yaml metadata at the top of README.md

Add basic info and TODOs to README

initial commit