fix(file-upload): align usage instructions with Ark UI

[pdzxc]

Clicking the FileUpload.Label causes the file upload dialog to appear again after selecting a file or canceling. There is a discrepancy in behavior between Park UI and Ark UI implementations.

Screen.Recording.2025-05-16.at.7.12.45.pm.mov

Park UI Implementation
https://park-ui.com/docs/components/file-upload

...
<FileUpload.Dropzone>
  <FileUpload.Label>Drop your files here</FileUpload.Label>
  <FileUpload.Trigger asChild>
    <Button size="sm">Open Dialog</Button>
  </FileUpload.Trigger>
</FileUpload.Dropzone>
...

Ark UI Implementation
https://ark-ui.com/docs/components/file-upload

...
<FileUpload.Label>Drop your files here</FileUpload.Label>
<FileUpload.Dropzone>
  <FileUpload.Trigger asChild>
    <Button size="sm">Open Dialog</Button>
  </FileUpload.Trigger>
</FileUpload.Dropzone>
...

[vercel]

@pdzxc is attempting to deploy a commit to the Personal Team on Vercel.

A member of the Team first needs to authorize it.