Adding style guide link to CONTRIBUTING.MD (#1730)

In response to reduxjs/react-redux#1495.

CONTRIBUTING.md

@@ -1,5 +1,7 @@
 # Contributing
-We are open to, and grateful for, any contributions made by the community.  By contributing to React Redux, you agree to abide by the [code of conduct](https://github.com/reduxjs/react-redux/blob/master/CODE_OF_CONDUCT.md).
+We are open to, and grateful for, any contributions made by the community.  By contributing to React Redux, you agree to abide by the [code of conduct](https://github.com/reduxjs/react-redux/blob/master/CODE_OF_CONDUCT.md). 
+
+Please review the [Redux Style Guide](https://redux.js.org/style-guide/style-guide) in the Redux docs to keep track of our best practices.
 
 ## Reporting Issues and Asking Questions
 Before opening an issue, please search the [issue tracker](https://github.com/reduxjs/react-redux/issues) to make sure your issue hasn't already been reported.