Initial commit - but way too late.

site/astro.config.mjs

@@ -0,0 +1,9 @@
+// @ts-check
+import { defineConfig } from "astro/config";
+import sitemap from "@astrojs/sitemap";
+
+// https://astro.build/config
+export default defineConfig({
+  site: process.env.PUBLIC_SITE_URL || "http://localhost:4321",
+  integrations: [sitemap()],
+});