Add badges and introduction for v2 (#129)

* Update README.md

Author: HoonBaek

README.md

@@ -1,5 +1,11 @@
 # sendbird-uikit
 
+[![Platform React](https://img.shields.io/badge/Platform-React-orange.svg)](https://reactjs.org)
+[![Language TypeScript](https://img.shields.io/badge/Language-TypeScript-orange.svg)](https://www.typescriptlang.org/)
+
+[**Beta version of Sendbird UIKit 3.0**](https://github.com/sendbird/sendbird-uikit-react/tree/develop-v3) has been released.
+Try to make your own application with this amazing version which contains **new modular components** and **UI components of elementary level**.
+
 > React based UI kit based on sendbird javascript SDK
 
 ## Getting Started