chore: update README

kiaking · kiaking · commit 2f7dba5b1cef · 2021-02-05T15:55:19.000+09:00
diff --git a/README.md b/README.md
@@ -5,33 +5,35 @@
 [![coverage](https://codecov.io/gh/vuejs/vuex-router-sync/branch/6.x/graph/badge.svg?token=4KJug3I5do)](https://codecov.io/gh/vuejs/vuex-router-sync)
 [![license](https://img.shields.io/npm/l/vuex-router-sync.svg?sanitize=true)](http://opensource.org/licenses/MIT)
 
+---
+
+:fire: **HEADS UP!** You're currently looking at Vuex Router Synx 6 branch which supports Vue 3. If you're looking for Vuex Router Sync 5 for Vue 2 support, [please check out `dev` branch](https://github.com/vuejs/vuex-router-sync).
+
+---
+
 Sync Vue Router's current `$route` as part of Vuex store's state.
 
 [中文版本 (Chinese Version)](README.zh-cn.md)
 
 ## Usage
 
 ``` bash
-# the latest version works only with vue-router >= 2.0
-npm install vuex-router-sync
-
-# for usage with vue-router < 2.0:
-npm install vuex-router-sync@2
+npm install vuex-router-sync@next
 ```
 
 ``` js
 import { sync } from 'vuex-router-sync'
 import store from './store' // vuex store instance
 import router from './router' // vue-router instance
 
-const unsync = sync(store, router) // done. Returns an unsync callback fn
+const unsync = sync(store, router) // done. returns an unsync callback fn
 
 // bootstrap your app...
 
-// During app/Vue teardown (e.g., you only use Vue.js in a portion of your app
+// during app/Vue teardown (e.g., you only use Vue.js in a portion of your app
 // and you navigate away from that portion and want to release/destroy
 // Vue components/resources)
-unsync() // Unsyncs store from router
+unsync() // unsyncs store from router
 ```
 
 You can optionally set a custom vuex module name:
@@ -48,6 +50,7 @@ sync(store, router, { moduleName: 'RouteModule' } )
   store.state.route.path   // current path (string)
   store.state.route.params // current params (object)
   store.state.route.query  // current query (object)
+  ...
   ```
 
 - When the router navigates to a new route, the store's state is updated.
