Add Stage 1 debiased test set (1485 questions)

Move rotation_270.jsonl to test split

Move rotation_180.jsonl to test split

Move rotation_90.jsonl to test split

Move rotation_0.jsonl to test split

Remove data/rotation_270.jsonl

Remove data/rotation_180.jsonl

Remove data/rotation_90.jsonl

Remove data/rotation_0.jsonl

Switch to JSONL format for HF preview + add PR contribution guide

Remove data/rotation_270.json (replaced by JSONL)

Remove data/rotation_180.json (replaced by JSONL)

Remove data/rotation_90.json (replaced by JSONL)

Remove data/rotation_0.json (replaced by JSONL)

Initial release: Real-3DQA v1.0 benchmark data + point clouds