Restructure blogs as Astro monorepo

sites/poetry/src/pages/rss.xml.js

@@ -0,0 +1,20 @@
+import rss from "@astrojs/rss";
+import { getCollection } from "astro:content";
+import { SITE_TITLE, SITE_DESCRIPTION } from "../consts";
+import { ACTIVE_BLOG_SITE } from "../blog-sites.js";
+
+export async function GET(context) {
+  const posts = (await getCollection(ACTIVE_BLOG_SITE.key)).sort(
+    (a, b) => b.data.pubDate.valueOf() - a.data.pubDate.valueOf(),
+  );
+
+  return rss({
+    title: SITE_TITLE,
+    description: SITE_DESCRIPTION,
+    site: context.site,
+    items: posts.map((post) => ({
+      ...post.data,
+      link: `/${post.id}/`,
+    })),
+  });
+}