Theme · Importing: VS Code themes read into Ely's palette, code palettes to choose

settings::read_vscode_theme reads a VS Code color theme, comments and
trailing commas and all: its type picks the mode, its colors and token
scopes name what they give, and the rest keep Ely's palette of that mode.
settings::ThemeImporter takes one dropped or browsed for, shows its name,
mode and count, and hands it over on Apply; a file that does not read
says why. theme::syntax_themes offers Ely's code colors, Quiet and Paper,
chosen through settings::SyntaxThemePicker, radio cards with a line of
code in each palette. A card's words now shrink as a plain block, so a
preview wraps inside the card at 280px.

examples/gallery/pages/theme/mod.rs

@@ -10,6 +10,7 @@ use gpui::{
 };
 
 mod editing;
+mod importing;
 
 use super::Page;
 use crate::ui::{section, specimen, specimens};
@@ -147,6 +148,7 @@ fn render(window: &mut Window, cx: &mut App) -> AnyElement {
             .child(track("spring", "spring · damping 0.75", motion::spring, cx)),
         )
         .child(editing::editor(window, cx))
+        .child(importing::importing(window, cx))
         .into_any_element()
 }