Aug 8

1. 16:46

   Add dataset card (provenance, stats, format, load instructions)

   jinshuoli
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   73eb01c
2. 16:25

   Add formal 1m train/val shards, source PGNs, metadata (part 2)

   jinshuoli
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   415391e
3. 16:21

   Add formal 1m train/val shards, source PGNs, metadata

   jinshuoli
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   c1d4338
4. 15:08

   initial commit

   jinshuoli
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   c23043b