fix: make import and usage separated in Button docs

packages/react/src/docs/components/Button.mdx

@@ -38,10 +38,10 @@ Displays a button or a component that looks like a button.
 
 ```tsx
 import { Button } from "@components/Button";
+```
 
-function ButtonDemo() {
-    return <Button>Button</Button>
-}
+```html
+<Button>Button</Button>
 ```
 
 ### Props