Update README to use Discord instead of Gitter

Author: Ives van Hoorne

README.md

@@ -1,8 +1,4 @@
-# [CodeSandbox](https://codesandbox.io)
-
-[![Join the chat at https://gitter.im/codesandbox-client/Lobby](https://badges.gitter.im/codesandbox-client/Lobby.svg)](https://gitter.im/codesandbox-client/Lobby?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-[![All Contributors](https://img.shields.io/badge/all_contributors-3-orange.svg?style=flat-square)](#contributors)
-[![Build Status](https://travis-ci.org/CompuIves/codesandbox-client.svg?branch=master)](https://travis-ci.org/CompuIves/codesandbox-client)
+# [CodeSandbox](https://codesandbox.io) [![Chat](https://img.shields.io/badge/chat-on%20discord-7289da.svg)](https://discord.gg/KE3TbEZ) [![All Contributors](https://img.shields.io/badge/all_contributors-3-orange.svg?style=flat-square)](#contributors) [![Build Status](https://travis-ci.org/CompuIves/codesandbox-client.svg?branch=master)](https://travis-ci.org/CompuIves/codesandbox-client)
 
 An online code editor with a focus on React.