ui: More component previews, UI component cleanup (#25302)

- Don't require ui component docs (this isn't really working)
- Add more component previews
- Update component preview style & navigation

Release Notes:

- N/A

crates/ui/src/components/stories.rs

@@ -1,8 +1,3 @@
-// We allow missing docs for stories as the docs will more or less be
-// "This is the ___ story", which is not very useful.
-#![allow(missing_docs)]
-mod avatar;
-mod button;
 mod context_menu;
 mod disclosure;
 mod icon;
@@ -15,8 +10,6 @@ mod tab;
 mod tab_bar;
 mod toggle_button;
 
-pub use avatar::*;
-pub use button::*;
 pub use context_menu::*;
 pub use disclosure::*;
 pub use icon::*;