Update README.md

Author: rwieruch

README.md

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 # React Redux Example
 
+[![Slack](https://slack-the-road-to-learn-react.wieruch.com/badge.svg)](https://slack-the-road-to-learn-react.wieruch.com/)
+
 * Found in [The Road to learn React](https://roadtoreact.com/)
 
 ![react-redux-example](https://user-images.githubusercontent.com/2479967/31530740-ab7ab6f0-b00c-11e7-8c6f-77e8094cb0b0.gif)