docs: add pottertech to CONTRIBUTORS.md

Co-Authored-By: Skip Potter <skip.potter.va@gmail.com>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CONTRIBUTORS.md

@@ -4,3 +4,4 @@ Thanks to everyone who has contributed to NanoClaw!
 
 - [Alakazam03](https://github.com/Alakazam03) — Vaibhav Aggarwal
 - [tydev-new](https://github.com/tydev-new)
+- [pottertech](https://github.com/pottertech) — Skip Potter