Write a script that extracts all elements and vaults from the Code of Points PDF into `data/`, following `docs/DATA_MODEL.md`. The PDF is not committed. **Done when:** - [ ] The script and instructions for running it are in `scripts/extract-cop/` - [ ] `data/` contains apparatus, element groups, elements, vaults, variant groups and images - [ ] The checks pass, and flagged entries are reviewed by hand - [ ] `data/README.md