2026-08-22 — Writing style guide: One canonical reference page

2026-08-22 — Writing style guide: One canonical reference page (docs/reference/writing-style.md) consolidates the scattered prose rules (British/US split, present tense, Diátaxis) and adds the punctuation rules (no em dash in list items — use a colon; capital after a colon; lower case after a semicolon), every rule labelled machine-enforced or review (enforcement-claims-are-facts). The DOCUMENTATION domain in .abcd/rules.json points at the guide (the OPINIONS pattern — point, don't copy); the machine-checkable punctuation subset is staged as itd-141 (native docs-lint now; Vale recorded in the intent as Related/SOTA and the named preferred future upgrade path; adopting an open-licensed guide — Google / Microsoft / GitLab / errata-ai styles — explored at the intent's SOTA pass). No ADR unless a new rule family emerges.