chore: improve types for markdown

packages/app/src/globals.d.ts

@@ -1 +1,4 @@
-declare module '*.md';
+declare module '*.md' {
+  const text: string;
+  export default text;
+}

packages/app/src/pages/workspace/[workspaceId]/[pageId].tsx

@@ -11,9 +11,6 @@ import { EditorHeader } from '@/components/header';
 import EdgelessToolbar from '@/components/edgeless-toolbar';
 import MobileModal from '@/components/mobile-modal';
 import { useAppState } from '@/providers/app-state-provider/context';
-/**
- * @type {string}
- */
 import exampleMarkdown from '@/templates/Welcome-to-the-AFFiNE-Alpha.md';
 import type { NextPageWithLayout } from '../..//_app';
 import WorkspaceLayout from '@/components/workspace-layout';