feat: add md-emfont component and format code

- Add `md-emfont` custom element for dynamic font loading
- Register `md-emfont` in component index
- Reformat `Article.tsx` and `index.ts` using double quotes and
  consistent spacing
- Fix indentation in `index.html`

src/components/index.ts

@@ -1,28 +1,30 @@
 // 导入自定义元素以注册
-import './md-dice';
-import './md-table';
-import './md-link';
-import './md-pins';
-import './md-bg';
-import './md-deck';
-import './md-commander/index';
-import './md-yarn-spinner';
-import './md-token';
-import './md-token-viewer';
+import "./md-dice";
+import "./md-table";
+import "./md-link";
+import "./md-pins";
+import "./md-bg";
+import "./md-emfont";
+import "./md-deck";
+import "./md-commander/index";
+import "./md-yarn-spinner";
+import "./md-token";
+import "./md-token-viewer";
 
 // 导出组件
-export { Article } from './Article';
-export type { ArticleProps } from './Article';
-export { MobileSidebar, DesktopSidebar } from './Sidebar';
-export type { SidebarProps } from './Sidebar';
-export { FileTreeNode, HeadingNode } from './FileTree';
+export { Article } from "./Article";
+export type { ArticleProps } from "./Article";
+export { MobileSidebar, DesktopSidebar } from "./Sidebar";
+export type { SidebarProps } from "./Sidebar";
+export { FileTreeNode, HeadingNode } from "./FileTree";
 
 // 导出数据类型
-export type { DiceProps } from './md-dice';
-export type { TableProps } from './md-table';
-export type { BgProps } from './md-bg';
-export type { YarnSpinnerProps } from './md-yarn-spinner';
-export type { TokenProps } from './md-token';
+export type { DiceProps } from "./md-dice";
+export type { TableProps } from "./md-table";
+export type { BgProps } from "./md-bg";
+export type { EmfontProps } from "./md-emfont";
+export type { YarnSpinnerProps } from "./md-yarn-spinner";
+export type { TokenProps } from "./md-token";
 
 // 导出 md-commander 相关
 export type {
@@ -39,10 +41,13 @@ export type {
   TrackerAttributeType,
   TrackerCommand,
   TrackerViewMode,
-} from './md-commander/types';
-export { TabBar } from './md-commander/TabBar';
-export { TrackerView } from './md-commander/TrackerView';
-export { CommanderEntries } from './md-commander/CommanderEntries';
-export { CommanderInput } from './md-commander/CommanderInput';
-export { useCommander } from './md-commander/hooks';
-export { initializeCommands, getCommands } from './md-commander/stores/commandsStore';
+} from "./md-commander/types";
+export { TabBar } from "./md-commander/TabBar";
+export { TrackerView } from "./md-commander/TrackerView";
+export { CommanderEntries } from "./md-commander/CommanderEntries";
+export { CommanderInput } from "./md-commander/CommanderInput";
+export { useCommander } from "./md-commander/hooks";
+export {
+  initializeCommands,
+  getCommands,
+} from "./md-commander/stores/commandsStore";