Feat: WIP terse code documentation

crates/ratatui/src/hint_bar.rs

@@ -1,8 +1,11 @@
+//! Bottom-bar keyboard hint renderer.
+
 use ratatui::text::{Line, Span};
 use ratatui::style::Style;
 
 use crate::theme;
 
+/// Build a styled line of key/action pairs for the hint bar.
 pub fn hint_line(pairs: &[(&str, &str)]) -> Line<'static> {
     let theme = theme::get();
     let key_style = Style::default().fg(theme.hint.key);