docs: add link to vuex 3 and adjust few things

docs/.vitepress/config.js

@@ -27,7 +27,13 @@ module.exports = {
         nav: [
           { text: 'Guide', link: '/guide/' },
           { text: 'API Reference', link: '/api/' },
-          { text: 'Release Notes', link: 'https://github.com/vuejs/vuex/releases' }
+          { text: 'Release Notes', link: 'https://github.com/vuejs/vuex/releases' },
+          {
+            text: 'v4.x',
+            items: [
+              { text: 'v3.x', link: 'https://vuex.vuejs.org/' }
+            ]
+          }
         ],
         sidebar: [
           {

docs/guide/plugins.md

@@ -87,8 +87,6 @@ The plugin will be used by default. For production, you will need [DefinePlugin]
 
 ## Built-in Logger Plugin
 
-> If you are using [vue-devtools](https://github.com/vuejs/vue-devtools) you probably don't need this.
-
 Vuex comes with a logger plugin for common debugging usage:
 
 ```js

docs/index.md

@@ -4,7 +4,7 @@
 This is the docs for Vuex 4, which works with Vue 3. If you're looking for docs for Vuex 3, which works with Vue 2, [please check it out here](https://vuex.vuejs.org/).
 :::
 
-Vuex is a **state management pattern + library** for Vue.js applications. It serves as a centralized store for all the components in an application, with rules ensuring that the state can only be mutated in a predictable fashion. It also integrates with Vue's official [devtools extension](https://github.com/vuejs/vue-devtools) to provide advanced features such as zero-config time-travel debugging and state snapshot export / import.
+Vuex is a **state management pattern + library** for Vue.js applications. It serves as a centralized store for all the components in an application, with rules ensuring that the state can only be mutated in a predictable fashion.
 
 ## What is a "State Management Pattern"?