README: Fix a Markdown link [ci skip]

README.md

@@ -62,7 +62,7 @@ The gem is available as open source under the terms of the [MIT License][mit-lic
 
 This project is intended to be a safe, welcoming space for collaboration.
 Everyone interacting in the Faraday::Http project’s codebases, issue trackers,
-chat rooms and mailing lists is expected to follow the [code of conduct].
+chat rooms and mailing lists is expected to follow the [code of conduct][code-of-conduct].
 
 [code-of-conduct]:     https://github.com/lostisland/faraday-http/blob/main/CODE_OF_CONDUCT.md
 [covenant]:            http://contributor-covenant.org