Release v3.3.0: Add experimental Codex support

- Restructured Codex files to .codex/ directory
- Updated README with simplified GitHub URL installation
- Added comprehensive release notes for v3.3.0
- Moved superpowers-codex script to .codex/superpowers-codex
- Updated all path references for new structure
- Installation now uses GitHub raw URL for streamlined setup

Codex support includes:
- Unified superpowers-codex script with bootstrap/use-skill/find-skills
- Cross-platform Node.js implementation
- Namespaced skills (superpowers:skill-name)
- Tool mapping (TodoWrite→update_plan, etc.)
- Clean skill display without frontmatter
- Personal skill override system

.codex/INSTALL.md

@@ -0,0 +1,35 @@
+# Installing Superpowers for Codex
+
+Quick setup to enable superpowers skills in Codex.
+
+## Installation
+
+1. **Clone superpowers repository**:
+   ```bash
+   mkdir -p ~/.codex/superpowers
+   cd ~/.codex/superpowers
+   git clone https://github.com/obra/superpowers.git .
+   ```
+
+2. **Create personal skills directory**:
+   ```bash
+   mkdir -p ~/.codex/skills
+   ```
+
+3. **Update ~/.codex/AGENTS.md** to include this superpowers section:
+   ```markdown
+   ## Superpowers System
+
+   <EXTREMELY_IMPORTANT>
+   You have superpowers. Superpowers teach you new skills and capabilities. RIGHT NOW run: `~/.codex/superpowers/.codex/superpowers-codex bootstrap` and follow the instructions it returns.
+   </EXTREMELY_IMPORTANT>
+   ```
+
+## Verification
+
+Test the installation:
+```bash
+~/.codex/superpowers/.codex/superpowers-codex bootstrap
+```
+
+You should see skill listings and bootstrap instructions. The system is now ready for use.