Add landing page for voicebox.sh

- Created a new landing page using Next.js 16, featuring a modern design with Tailwind CSS.
- Implemented essential components including Header, Footer, and DownloadSection for user navigation and download options.
- Configured Tailwind CSS and PostCSS for styling, and set up TypeScript for type safety.
- Added a README with setup instructions, project structure, and deployment guidelines.
- Integrated GitHub links for easy access to the repository and releases.
- Established a consistent UI with reusable components and responsive design.

landing/src/lib/utils.ts

@@ -0,0 +1,6 @@
+import { type ClassValue, clsx } from 'clsx';
+import { twMerge } from 'tailwind-merge';
+
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs));
+}