Add mailing list link to Community section

README.md

@@ -78,6 +78,7 @@ The GitOps Toolkit is always looking for new contributors and there are a multit
 - Talk to us in the #flux channel on [CNCF Slack](https://slack.cncf.io/)
 - Join the [planning discussions](https://github.com/fluxcd/toolkit/discussions)
 - And if you are completely new to the GitOps Toolkit, take a look at our [Get Started guide](get-started/index.md) and give us feedback
+- To be part of the conversation about Flux's development, [join the flux-dev mailing list](https://lists.cncf.io/g/cncf-flux-dev).
 - Check out [how to contribute](contributing/index.md) to the project
 
 We are looking forward to seeing you with us!