feat: initialize project with Tailwind CSS, TypeScript, and basic layout

- Add globals.css to import Tailwind CSS styles
- Create layout.tsx for the root layout with metadata and font integration
- Implement Header component with title and subtitle
- Set up tsconfig.json for TypeScript configuration

src/components/Header.tsx

@@ -0,0 +1,10 @@
+const Header: React.FC = () => {
+    return (
+        <header className="w-full flex flex-col items-center gap-1 py-4 border-b border-gray-400">
+            <small className="text-sm">tuna2134の休憩</small>
+            <h1 className="text-4xl font-bold">tuna2134</h1>
+        </header>
+    )
+}
+
+export default Header;