Give the User Guide real breathing room between paragraphs

Every paragraph, note and entry was a separate label stacked with only
egui's default item spacing between them, so sections didn't read as
clear breaks. Scope a larger item_spacing to the User Guide's own Ui
(not the shared section/note/body helpers) so the Markdown Cheatsheet,
which uses the same helpers, is unaffected.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/help.rs

@@ -27,14 +27,20 @@ pub fn user_guide_window(ctx: &egui::Context, open: &mut bool) {
     egui::Window::new("📖 User Guide")
         .open(open)
         .resizable(true)
-        .default_width(640.0)
-        .default_height(620.0)
+        .default_width(720.0)
+        .default_height(680.0)
         .show(ctx, |ui| {
             egui::ScrollArea::vertical().show(ui, user_guide_body);
         });
 }
 
 fn user_guide_body(ui: &mut egui::Ui) {
+    // More breathing room than egui's default item spacing — scoped to this
+    // `Ui` (and so inherited by every child it lays out below), not to the
+    // shared `section`/`note`/`body`/`entries` helpers themselves, so the
+    // Markdown Cheatsheet's own window is unaffected.
+    ui.spacing_mut().item_spacing.y = 12.0;
+
     intro(
         ui,
         "What every window, menu item and setting does. For markdown and \
@@ -604,7 +610,9 @@ fn syntax(ui: &mut egui::Ui, id: &str, rows: &[(&str, &str)]) {
 /// rather than side by side — for descriptions too long to sit in
 /// `syntax`'s two-column grid without either overflowing or forcing the
 /// whole window wider to avoid wrapping, since a `Grid` sizes each column to
-/// its widest cell instead of wrapping.
+/// its widest cell instead of wrapping. Relies on the caller's own
+/// `item_spacing` for the gap between rows, rather than hand-adding one here
+/// on top of it.
 fn entries(ui: &mut egui::Ui, rows: &[(&str, &str)]) {
     for (label, desc) in rows {
         ui.label(
@@ -613,6 +621,5 @@ fn entries(ui: &mut egui::Ui, rows: &[(&str, &str)]) {
                 .color(egui::Color32::from_rgb(120, 170, 120)),
         );
         ui.label(*desc);
-        ui.add_space(6.0);
     }
 }