feat(docs): enhance documentation site with internationalization and layout updates

- Updated the demo API to support locale-based content rendering.
- Refactored the main layout to accommodate language-specific metadata and routing.
- Introduced new components for blog and documentation pages, ensuring proper language handling.
- Added styles for improved UI consistency across different sections.
- Removed deprecated layout files and streamlined the structure for better maintainability.

apps/docs/app/[lang]/og/docs/[...slug]/route.tsx

@@ -0,0 +1,31 @@
+import { getPageImageUrl, source } from '@/lib/source';
+import { i18n } from '@/lib/i18n';
+import { notFound } from 'next/navigation';
+import { ImageResponse } from 'next/og';
+import { generate as DefaultImage } from 'fumadocs-ui/og';
+import { appName } from '@/lib/shared';
+
+export const revalidate = false;
+
+export async function GET(_req: Request, { params }: RouteContext<'/[lang]/og/docs/[...slug]'>) {
+  const { lang, slug } = await params;
+  const page = source.getPage(slug.slice(0, -1), lang);
+  if (!page) notFound();
+
+  return new ImageResponse(
+    <DefaultImage title={page.data.title} description={page.data.description} site={appName} />,
+    {
+      width: 1200,
+      height: 630,
+    },
+  );
+}
+
+export function generateStaticParams() {
+  return i18n.languages.flatMap((lang) =>
+    source.getPages(lang).map((page) => ({
+      lang,
+      slug: getPageImageUrl(page).segments,
+    })),
+  );
+}