Add slack channel to README (#1261)

- fix github actions badge url
- refine twitter badge

![image](https://github.com/apache/incubator-fury/assets/20042607/8571d6c1-241a-441d-85d8-8a7a98cac085)

README.md

@@ -2,13 +2,13 @@
   <img width="65%" alt="" src="docs/images/logo/fury_github_banner.png"><br>
 </div>
 
-[![Build Status](https://img.shields.io/github/actions/workflow/status/apache/incubator-fury/ci.yml?branch=main&style=for-the-badge&label=GITHUB%20ACTIONS&logo=github)](https://github.com/apache/incubator-fury)
-[![Twitter](https://img.shields.io/twitter/follow/fury_community?logo=twitter&style=for-the-badge)](https://twitter.com/fury_community)
+[![Build Status](https://img.shields.io/github/actions/workflow/status/apache/incubator-fury/ci.yml?branch=main&style=for-the-badge&label=GITHUB%20ACTIONS&logo=github)](https://github.com/apache/incubator-fury/actions/workflows/ci.yml)
+[![Slack Channel](https://img.shields.io/badge/slack-join-3f0e40?logo=slack&style=for-the-badge)](https://join.slack.com/t/fury-project/shared_invite/zt-1u8soj4qc-ieYEu7ciHOqA2mo47llS8A)
+[![Twitter](https://img.shields.io/badge/@fury__community-follow-blue?logo=twitter&style=for-the-badge)](https://twitter.com/fury_community)
 [![Maven Version](https://img.shields.io/maven-central/v/org.furyio/fury-core?style=for-the-badge)](https://search.maven.org/#search|gav|1|g:"org.furyio"%20AND%20a:"fury-core")
 
 
-
-Apache Fury (incubating) is a blazing-fast multi-language serialization framework powered by **JIT** (just-in-time compilation) and **zero-copy**, providing up to 170x performance and ultimate ease of use.
+**Apache Fury (incubating)** is a blazing-fast multi-language serialization framework powered by **JIT** (just-in-time compilation) and **zero-copy**, providing up to 170x performance and ultimate ease of use.
 
 https://fury.apache.org