Add installable create-plan skills for codex, claude-code, and opencode

README.md

@@ -1,3 +1,61 @@
 # ai-coding-skills
 
-Cross-agent coding skills for Codex, Claude Code, and OpenCode
+Cross-agent skill collection for **Codex**, **Claude Code**, and **OpenCode**.
+
+This repo is organized similarly to `obra/superpowers` and is designed to scale to many skills over time.
+
+## Goals
+
+- Keep skills portable across coding agents.
+- Keep each skill self-contained (`skills/<skill-name>/SKILL.md` + optional resources).
+- Enforce requirement checks for skills that depend on Superpower skills.
+
+## Repository Layout
+
+```text
+ai-coding-skills/
+├── README.md
+├── docs/
+│   ├── repository-structure.md
+│   └── requirements-gate.md
+├── skills/
+│   ├── _template/
+│   │   └── SKILL.md
+│   └── create-plan/
+│       ├── codex/
+│       ├── claude-code/
+│       └── opencode/
+├── .codex/
+├── .claude-plugin/
+├── .opencode/
+│   └── plugins/
+├── commands/
+├── hooks/
+└── tests/
+```
+
+## Skills
+
+| Skill | Agent Variant | Purpose | Status |
+|---|---|---|---|
+| create-plan | codex | Structured planning with milestones + runbook-first execution workflow | Ready |
+| create-plan | claude-code | Structured planning with milestones + runbook-first execution workflow | Ready |
+| create-plan | opencode | Structured planning with milestones + runbook-first execution workflow | Ready |
+
+See install instructions: `docs/install.md`
+
+## Requirement Gate (Superpowers dependency)
+
+If a skill depends on Superpower skills (`https://github.com/obra/superpowers`), it must include an explicit prerequisite block in `SKILL.md` and fail fast with clear instructions when requirements are missing.
+
+See: `docs/requirements-gate.md`
+
+## Compatibility Policy
+
+Each skill added to this repo should specify support status for:
+
+- Codex
+- Claude Code
+- OpenCode
+
+Use the template at `skills/_template/SKILL.md`.