Update CODE_OF_CONDUCT.md with email address

Author: djhoese

CODE_OF_CONDUCT.md

@@ -60,7 +60,7 @@ representative at an online or offline event.
 
 Instances of abusive, harassing, or otherwise unacceptable behavior may be
 reported to the community leaders responsible for enforcement at
-[INSERT CONTACT METHOD].
+vispy-conduct@groups.io.
 All complaints will be reviewed and investigated promptly and fairly.
 
 All community leaders are obligated to respect the privacy and security of the
@@ -130,4 +130,3 @@ at [https://www.contributor-covenant.org/translations][translations].
 [Mozilla CoC]: https://github.com/mozilla/diversity
 [FAQ]: https://www.contributor-covenant.org/faq
 [translations]: https://www.contributor-covenant.org/translations
-