message: fix `CODE_OF_CONDUCT` link in `CONTRIBUTING.md`
diff: @@ -19,7 +19,7 @@ First of all, thank you for taking your time to contribute to ink!
  ## Code of Conduct
  We are a friendly and welcoming open source community.
  -You can find our code of conduct [here](CODE_OF_CONDUCT.md).
  +You can find our code of conduct [here](CODE_OF_CONDUCT.adoc).
  ## During Development
  