Update README.md (#120)

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

* Update README.md

Author: makseq

README.md

@@ -6,7 +6,7 @@
     <p>Its purpose is to help you label different types of data using a simple interface with a standardized output format. It's mobile-friendly and fast.</p>
 </div>
 
-[Website](https://labelstud.io/) • [Docs](https://labelstud.io/docs) • [Slack](https://docs.google.com/forms/d/e/1FAIpQLSdLHZx5EeT1J350JPwnY2xLanfmvplJi6VZk65C2R4XSsRBHg/viewform?usp=sf_link) • [Twitter](https://twitter.com/heartexlabs)
+[Website](https://labelstud.io/) • [Docs](https://labelstud.io/docs) • [Twitter](https://twitter.com/heartexlabs) • [Join Slack Community <img src="https://go.heartex.net/docs/images/slack-mini.png" width="18px"/>](https://docs.google.com/forms/d/e/1FAIpQLSdLHZx5EeT1J350JPwnY2xLanfmvplJi6VZk65C2R4XSsRBHg/viewform?usp=sf_link)
 
 ![GitHub](https://img.shields.io/github/license/heartexlabs/label-studio?logo=heartex) [![Build Status](https://travis-ci.com/heartexlabs/label-studio.svg?branch=master)](https://travis-ci.com/heartexlabs/label-studio) [![codecov](https://codecov.io/gh/heartexlabs/label-studio/branch/master/graph/badge.svg)](https://codecov.io/gh/heartexlabs/label-studio) ![GitHub release](https://img.shields.io/github/v/release/heartexlabs/label-studio?include_prereleases) [![Gitter](https://badges.gitter.im/label-studio/community.svg)](https://gitter.im/label-studio/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)