Updated readme to reference discord instead of slack (#87)

Author: m-thompson-code

README.md

@@ -11,7 +11,7 @@
 
 This project is supported by [Bitovi, a React consultancy](https://www.bitovi.com/frontend-javascript-consulting/react-consulting). You can get help or ask questions on our:
 
-- [Slack Community](https://www.bitovi.com/community/slack)
+- [Discord Community](https://discord.gg/J7ejFsZnJ4)
 - [Twitter](https://twitter.com/bitovi)
 
 Or, you can hire us for training, consulting, or development. [Set up a free consultation.](https://www.bitovi.com/frontend-javascript-consulting/react-consulting)