Update news for v3

Author: ahangarha

README.md

@@ -5,7 +5,7 @@
 [![Ruby](https://github.com/reactjs/react-rails/actions/workflows/ruby.yml/badge.svg)](https://github.com/reactjs/react-rails/actions/workflows/ruby.yml)
 
 ## News
-v2.7.1 is released. Please try it out and report any issues. We'll try to address any critical issues ASAP. We're going shortly release 3.0, which fully support Shakapacker v6, including SSR.
+V3.0.0 is released with Shakapacker v6 support, including SSR. Please try it out and report any issues. We'll try to address any critical issues ASAP.
 
 ## Summary
 React-Rails is a flexible tool to use [React](http://facebook.github.io/react/) with Rails. The benefits: