Add a demo for using a `Select` component within a `Drawer` (requires `position="popper"`)

[TimChild]

I had some trouble using the rx.select component within a drawer since a recent update to react . Setting the position to "popper" fixes it. Thought I'd just add a quick example to the docs so it's easier to find in the future.

Related to: https://github.com/reflex-dev/reflex/issues/5002

Edit: While "popper" works in the drawer, it is technically a workaround since it does change the behavior... See example in issue linked.