update docs

Author: kazupon

README.md

@@ -30,7 +30,7 @@ Internationalization plugin for Vue.js
 <br/>
 <br/>
 
-## Status: Beta ![Test](https://github.com/intlify/vue-i18n-next/workflows/Test/badge.svg)
+## Status: RC ![Test](https://github.com/intlify/vue-i18n-next/workflows/Test/badge.svg)
 
 - [Documetantion](https://vue-i18n-next.intlify.dev/) (beta)
 - If you use stable Vue I18n version, see this [repository](https://github.com/kazupon/vue-i18n)