docs: add link to community slack (#639)

README.md

@@ -1,11 +1,13 @@
 # nyc
 
-[![Join the chat at https://gitter.im/istanbuljs/nyc](https://badges.gitter.im/istanbuljs/nyc.svg)](https://gitter.im/istanbuljs/nyc?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 [![Build Status](https://travis-ci.org/istanbuljs/nyc.svg?branch=master)](https://travis-ci.org/istanbuljs/nyc)
 [![Coverage Status](https://coveralls.io/repos/bcoe/nyc/badge.svg?branch=)](https://coveralls.io/r/bcoe/nyc?branch=master)
 [![NPM version](https://img.shields.io/npm/v/nyc.svg)](https://www.npmjs.com/package/nyc)
 [![Windows Tests](https://img.shields.io/appveyor/ci/bcoe/nyc-ilw23/master.svg?label=Windows%20Tests)](https://ci.appveyor.com/project/bcoe/nyc-ilw23)
 [![Conventional Commits](https://img.shields.io/badge/Conventional%20Commits-1.0.0-yellow.svg)](https://conventionalcommits.org)
+[![community slack](http://devtoolscommunity.herokuapp.com/badge.svg)](http://devtoolscommunity.herokuapp.com)
+
+_Having problems? want to contribute? join our [community slack](http://devtoolscommunity.herokuapp.com)_.
 
 Istanbul's state of the art command line interface, with support for: