first commit

src/pages/robots.txt.ts

@@ -0,0 +1,14 @@
+import type { APIRoute } from "astro";
+
+export const GET: APIRoute = ({ site }) => {
+  const origin = (site ?? new URL("https://example.com")).toString().replace(/\/$/, "");
+  return new Response(
+    `User-agent: *
+Allow: /
+Disallow: /admin
+
+Sitemap: ${origin}/sitemap.xml
+`,
+    { headers: { "Content-Type": "text/plain; charset=utf-8" } },
+  );
+};