docs: fix SyntaxError (#987)

Author: codersjj

website/docs/src/pages/getting-started/usage.mdx

@@ -59,7 +59,7 @@ export default function App() {
   return (
     <Sandpack
       files={{
-        '/Wrapper.js': \`export default () => return "";\`,
+        '/Wrapper.js': \`export default () => "";\`,
       
         '/Button.js': {
           code: \`export default () => {