Link from CONTRIBUTING to the code of conduct.
Link from CONTRIBUTING to the code of conduct.

Contributes to https://github.com/dart-lang/site-www/issues/1792.

Closes https://github.com/dart-lang/sdk/pull/40024
https://github.com/dart-lang/sdk/pull/40024

GitOrigin-RevId: a05469ef645eaaedac29a9aba141b083dcfbd378
Change-Id: Idef17931fe63038ba09873f1257ad0077e51863a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/130731
Reviewed-by: Michael Thomsen <5977a55c75bb4612004451a56b0b4c22d9d3311d@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk