Update code_reviewers.md (#958)

Author: ShadowMitia

Diff for: contents/code_reviews/code_reviewers.md

@@ -67,3 +67,4 @@ Chapters | [@leios]
 [@ntindle]: https://github.com/ntindle
 [@amaras]: https://github.com/amaras
 [@ShadowMitia]: https://github.com/ShadowMitia
+[@PeanutbutterWarrior]: https://github.com/PeanutbutterWarrior