Add dev mailing list and remove a duplicated Zulip link (#341)

README.md

@@ -28,16 +28,13 @@ Documentation is available at https://polaris.apache.org, including
 [Polaris management API doc](https://polaris.apache.org/index.html#tag/polaris-management-service_other)
 and [Apache Iceberg REST API doc](https://polaris.apache.org/index.html#tag/Configuration-API).
 
+Subscribe to the [dev mailing list][dev-list] to join discussions. Check out the [CONTRIBUTING guide](CONTRIBUTING.md)
+for contribution guidelines.
+
 [![Zulip](https://img.shields.io/badge/Zulip-Chat-blue?color=3d4db3&logo=zulip&style=for-the-badge&logoColor=white)](https://polaris-catalog.zulipchat.com/)
 [![Build Status](https://img.shields.io/github/actions/workflow/status/apache/polaris/gradle.yml?branch=main&label=Main%20CI&logo=Github&style=for-the-badge)](https://github.com/apache/polaris/actions/workflows/gradle.yml?query=branch%3Amain)
 
-## Community
-
-Join us on the [Apache Polaris public chat](https://polaris-catalog.zulipchat.com/) (no invite needed).
-
-## Development
-
-See [CONTRIBUTING](CONTRIBUTING.md) for contribution requirements.
+[dev-list]: mailto:[email protected]
 
 ## Building and Running