Document UI modules

Co-Authored-By: Antonio Scandurra <me@as-cii.com>

crates/ui/src/prelude.rs

@@ -1,3 +1,5 @@
+//! The prelude of this crate. When building UI in zed you almost always want to import this.
+
 pub use gpui::prelude::*;
 pub use gpui::{
     div, px, relative, rems, AbsoluteLength, DefiniteLength, Div, Element, ElementId,

crates/ui/src/ui.rs

@@ -3,8 +3,6 @@
 //! This crate provides a set of UI primitives and components that are used to build all of the elements in Zed's UI.
 //!
 
-#![doc = include_str!("../docs/building-ui.md")]
-
 mod clickable;
 mod components;
 mod disableable;

crates/ui/src/utils.rs

@@ -1,3 +1,5 @@
+//! UI-related utilities (e.g. converting dates to a human-readable form).
+
 mod format_distance;
 
 pub use format_distance::*;