Update README.md

Remove obsolete unsplit Parquet

Add deterministic train validation test splits

Remove legacy duplicate exports

Document full unsplit QM9 corpus

Add uv reproducibility script

Add complete QM9 metadata parquet

Canonicalize train atom/coord ordering with RDKit ranks

Keep only atoms and coords in QM9

Add QM9 exclusion list

Add QM9 preparation script

Create README.md

Add QM9 parquet splits

initial commit