SUMMARY.md drives the mdBook build and mdBook renders only what SUMMARY
references, so 31 of the 52 pages in docs/ were being written, reviewed
and merged without ever appearing on the published site: 25 of the 26
specs (only video-background-audio was listed), plus build-desktop-
packages, build-windows and defect-windows.
The specs are grouped into themed sections — playback, library and
browsing, downloads and offline, tooling and build — because a flat list
of 28 is not navigable, with SPEC-TEMPLATE and SPEC-REVIEW-CHECKLIST kept
together as the process docs someone reaches for before writing a spec.