Add initial setup for frontend and backend

This commit includes configurations and boilerplate code for both frontend and backend. The frontend uses Next.js with Tailwind CSS, while the backend is built with FastAPI. Various essential files like `tsconfig.json`, `requirements.txt`, and `.gitignore` have been added to kickstart the development process.

frontend/postcss.config.mjs

@@ -0,0 +1,5 @@
+const config = {
+  plugins: ["@tailwindcss/postcss"],
+};
+
+export default config;