init: astro publish site with newsletter, search, and actions workflow

astro.config.mjs

@@ -0,0 +1,11 @@
+// @ts-check
+
+import mdx from '@astrojs/mdx';
+import sitemap from '@astrojs/sitemap';
+import { defineConfig } from 'astro/config';
+
+// https://astro.build/config
+export default defineConfig({
+	site: process.env.SITE_URL ?? 'https://example.com',
+	integrations: [mdx(), sitemap()],
+});