fix(docs): css import order bug in tailwindcss docs and example (#10561)
### Description
Fixes #10538
Updated the Tailwind CSS setup docs and the `examples/with-tailwind`
example to remove the `@import 'tailwindcss'` from the UI package’s
`styles.css`. Tailwind is now imported only once in the app’s
`globals.css` to ensure correct CSS priority.
Tested according to the related GitHub issue and confirmed this change
fixes the CSS priority problem affecting utility classes like
`.grid-cols-*`