(docs): Improve coding agent skill mention in README.md (#1212)

Author: NandanPrabhu

README.md

@@ -14,7 +14,13 @@
 >
 > We'd love for you to try it out and share your feedback! Please [open an issue](https://github.com/auth0/Auth0.swift/issues) if you encounter any problems or have suggestions.
 >
-> 📚 [Migration Guide](https://github.com/auth0/Auth0.swift/blob/3.0.0-beta.2/V3_MIGRATION_GUIDE.md)  •  📦 [v3 Changelog](https://github.com/auth0/Auth0.swift/blob/3.0.0-beta.2/CHANGELOG.md)
+> 📚 [Migration Guide](https://github.com/auth0/Auth0.swift/blob/3.0.0-beta.2/V3_MIGRATION_GUIDE.md)  •  📦 [v3 Changelog](https://github.com/auth0/Auth0.swift/blob/3.0.0-beta.2/CHANGELOG.md)  •  🤖 [Migration Skill](https://github.com/auth0/agent-skills/tree/main/plugins/auth0/skills/auth0-swift-major-migration)
+>
+> **Skill for Coding Agents:** If you use coding agents such as Claude Code or Cursor, add the Auth0.swift migration skill to automate the upgrade:
+> ```
+> npx skills add auth0/agent-skills --skill auth0-swift-major-migration
+> ```
+>
 
 ## Documentation