[chore] Add Zulip channel badge
[![Verify Build Workflow](https://github.com/Apicurio/apicurio-registry/workflows/Verify%20Build%20Workflow/badge.svg)](https://github.com/Apicurio/apicurio-registry/actions?query=workflow%3A%22Verify+Build+Workflow%22)
+[![Join the chat at https://apicurio.zulipchat.com/](https://img.shields.io/badge/zulip-join_chat-brightgreen.svg)](https://apicurio.zulipchat.com/)
[![Automated Release Notes by gren](https://img.shields.io/badge/%F0%9F%A4%96-release%20notes-00B2EE.svg)](https://github-tools.github.io/github-release-notes/)
# Apicurio Registry
