Feat: WIP terse code documentation

crates/ratatui/src/spectrum.rs

@@ -1,3 +1,5 @@
+//! 32-band frequency spectrum bar display.
+
 use crate::theme;
 use ratatui::buffer::Buffer;
 use ratatui::layout::Rect;
@@ -6,6 +8,7 @@ use ratatui::widgets::Widget;
 
 const BLOCKS: [char; 8] = ['\u{2581}', '\u{2582}', '\u{2583}', '\u{2584}', '\u{2585}', '\u{2586}', '\u{2587}', '\u{2588}'];
 
+/// 32-band spectrum analyzer using block characters.
 pub struct Spectrum<'a> {
     data: &'a [f32; 32],
     gain: f32,