docs(readme): updated instruction for vue 3 (#1629)

Author: yangzii0920

README.md

@@ -34,12 +34,14 @@ with GitHub sponsors!
 
 Huge thanks to the [sponsors](https://github.com/sponsors/sagalbot) and [contributors](https://github.com/sagalbot/vue-select/graphs/contributors) that make Vue Select possible!
 
-## Install
+## Get started
+
+**Vue 3 / Vue Select 4.x-beta**
 
 > Vue 3 support is on the `beta` channel: `vue-select@beta`, and will become the new default when `v4` is released. See [#1579](https://github.com/sagalbot/vue-select/issues/1597) for more details!
 
+Install:
 
-**Vue 3 / Vue Select 4.x-beta**
 ```bash
 yarn add vue-select@beta
 
@@ -48,7 +50,32 @@ yarn add vue-select@beta
 npm install vue-select@beta
 ```
 
+Then, import and register the component:
+
+```js
+# main.ts or main.js
+
+import { createApp } from "vue";
+import App from "./App.vue";
+
+import { VueSelect } from "vue-select";
+
+createApp(App)
+    .component("v-select", VueSelect)
+    .mount("#app");
+```
+
+The component itself does not include any CSS. You'll need to include it separately in your Component.vue:
+```vue
+<style>
+@import "vue-select/dist/vue-select.css";
+</style>
+```
+
 **Vue 2 / Vue Select 3.x**
+
+Install:
+
 ```bash
 yarn add vue-select