docs: add vaul-vue scale background note (#481)

apps/www/src/content/docs/components/drawer.md

@@ -53,6 +53,13 @@ import {
   </Drawer>
 </template>
 ```
+### Scale Background
+
+If you want the background to have a zoom effect, you need to add the `vaul-drawer-wrapper` attribute to the root component.
+
+```html
+<div vaul-drawer-wrapper id="app"></div>
+```
 
 ## Examples