Add update instructions for Native Codex skills support

.codex/Update.md

@@ -0,0 +1,17 @@
+# Using Codex native skills support with Superpowers
+
+With the introduction of native support for skills in codex (https://github.com/
+  openai/codex/blob/main/docs/skills.md), we don't have to use legacy superpowers hook.
+
+# Steps to update from legacy installation
+1) Directory: put skills under `~/.codex/skills` (one folder per skill with `SKILL.md`).
+2) Enable feature: add to `~/.codex/config.toml`:
+   ```toml
+   [features]
+   skills = true
+   ```
+3) Restart Codex CLI fully, then start a new session. A “## Skills” block should list the skills from `~/.codex/skills`.
+
+Notes
+- Hooks: Codex does not load `~/.codex/hooks/hooks.json`; the native skills system handles discovery. You can keep `session-start.sh` if you want custom messaging, but it isn’t required for skills.
+- Legacy superpowers: old path `~/.config/superpowers/skills` is ignored; move anything useful into `~/.codex/skills`.