Create documentation spec for Claude code skills

[nhorton]

Create a world-class document type definition for Claude Code skill files that provides detailed guidance on:

• Skill types (meta-skills, step skills, standalone)
• File structure with YAML frontmatter and markdown content
• Description writing best practices for search discoverability
• Instruction organization with progressive disclosure
• Hook configuration (Stop, PreToolUse, UserPromptSubmit)
• Quality validation loops with promise tag pattern
• Input/output specification with document type references
• Work branch conventions for context accumulation
• Completion patterns for workflows vs standalone skills
• Common patterns and anti-patterns to avoid
• Complete worked examples

This spec enables consistent, high-quality skill definitions that AI agents can reliably execute.