write-a-skill

Skill-author skill: create new agent skills with proper structure, progressive disclosure, and bundled resources. Derived from Matt Pocock's MIT-licensed write-a-skill with: (1) 3 stdlib Python validation tools (description validator, structure validator, review-checklist runner — all enforcing Matt's 6-item checklist), (2) 4 references citing 7-8 authoritative sources each (progressive disclosure principles, description design patterns, quality gates, companion tooling), (3) cs-skill-author persona agent + /cs:write-a-skill slash command. Matt's voice and 3-phase workflow (Gather → Draft → Review) preserved verbatim per MIT.