add link references to code_of_conduct.md (#572)

Author: tobyhodges

CODE_OF_CONDUCT.md

@@ -8,4 +8,5 @@ we pledge to follow the [Carpentry Code of Conduct][coc].
 Instances of abusive, harassing, or otherwise unacceptable behavior
 may be reported by following our [reporting guidelines][coc-reporting].
 
-{% include links.md %}
+[coc]: https://docs.carpentries.org/topic_folders/policies/code-of-conduct.html
+[coc-reporting]: https://docs.carpentries.org/topic_folders/policies/incident-reporting.html