chore: update

Author: antfu

README.md

@@ -20,6 +20,8 @@ import VueComposisionAPI from '@vue/composition-api'
 Vue.use(VueComposisionAPI)
 ```
 
+See [`playground/`](./playground/) as an example.
+
 ###### Vite
 
 ```ts
@@ -90,7 +92,6 @@ It's made possible by transforming the SFC back to normal `<script>` and let the
 
 </details>
 
-
 ## Sponsors
 
 <p align="center">