docs: add statement about the upstream repo

Author: kbulgakov-exo

README.md

@@ -11,12 +11,8 @@
 
 ## Core Maintainers - Sponsoring companies
 
-_This project is maintained for free by these people using both their free time and their company work time._
-
-- [Thibault Malbranche](https://github.com/Titozzz) ([Twitter @titozzz](https://twitter.com/titozzz)) from [Brigad](https://www.brigad.co/en-gb/about-us)
-- [Jamon Holmgren](https://github.com/jamonholmgren) ([Twitter @jamonholmgren](https://twitter.com/jamonholmgren)) from [Infinite Red](https://infinite.red/react-native)
-- [Alexander Sklar](https://github.com/asklar) ([Twitter @alexsklar](https://twitter.com/alexsklar)) from [React Native Windows @ Microsoft](https://microsoft.github.io/react-native-windows/)
-- [Chiara Mooney](https://github.com/chiaramooney) from [React Native Windows @ Microsoft](https://microsoft.github.io/react-native-windows/)
+_This project is a fork of https://github.com/react-native-webview/react-native-webview. 
+Please refer to that repository for full credits._
 
 ## Platforms Supported