[ FEATURE ] Add exit animations

[billnye2]

Is your feature request related to a problem? Please describe. Hey really cool lib, I'm gonna try using it. Noticed that the enter animations are nice and mimic og shadcn nicely. But also see that exit animations aren't implemented yet, for instance the dropdown menu immediately disappears on exit rather than animating with a fade out. This was tested on the web demo, not sure what mobile side looks like yet. I believe shadcn added exit animations to his lib around a year ago. Wondering if this is on the roadmap?

Great library, Thanks!