docs: replace README with Next.js boilerplate template

Updated README.md from a detailed OllaHub project description to the standard Next.js getting started template, likely to initialize or reset the project as a Next.js application.

components/mode-toggle.tsx

@@ -0,0 +1,27 @@
+"use client";
+
+import { Moon, Sun } from "lucide-react";
+import { useTheme } from "next-themes";
+import { useEffect, useState } from "react";
+
+export function ModeToggle() {
+  const { theme, setTheme } = useTheme();
+  const [mounted, setMounted] = useState(false);
+  useEffect(() => setMounted(true), []);
+  if (!mounted) return null;
+  const isDark =
+    theme === "dark" ||
+    (!theme &&
+      typeof window !== "undefined" &&
+      window.matchMedia("(prefers-color-scheme: dark)").matches);
+  return (
+    <button
+      aria-label="Alternar tema"
+      className="inline-flex h-9 items-center gap-2 rounded-md border border-[var(--border)] bg-[var(--surface)] px-3 text-sm transition-colors hover:bg-[color-mix(in_oklab,var(--surface),black_6%)] focus:outline-none focus-visible:ring-2 focus-visible:ring-[var(--accent)]"
+      onClick={() => setTheme(isDark ? "light" : "dark")}
+    >
+      {isDark ? <Sun className="h-4 w-4" /> : <Moon className="h-4 w-4" />}
+      <span className="hidden sm:inline">{isDark ? "Light" : "Dark"}</span>
+    </button>
+  );
+}