feat: include full post content in RSS feed

Full text in an RSS feed is more convenient for users, see this article[1] for more information.

Summary of the motivation:
- Easier for users because they don't have to visit the blog
- Text within the article can be searched with the reader
- Offline reading will be possible

[1]: https://openrss.org/blog/full-text-in-rss-please

Author: goestav

bun.lock

@@ -18,6 +18,8 @@
     "@tailwindcss/forms": "^0.5.10",
     "@tailwindcss/typography": "^0.5.16",
     "@types/bun": "latest",
+    "@types/markdown-it": "^14.1.2",
+    "@types/sanitize-html": "^2.16.0",
     "fast-xml-parser": "^4.5.3",
     "kleur": "^4.1.5",
     "prettier": "^3.5.3",
@@ -30,6 +32,8 @@
     "@astrojs/tailwind": "^5.1.5",
     "@astrojs/ts-plugin": "^1.10.4",
     "astro": "^4.16.18",
+    "markdown-it": "^14.1.0",
+    "sanitize-html": "^2.17.0",
     "tailwindcss": "^3.4.17"
   }
 }

package.json

@@ -1,6 +1,10 @@
 import rss from "@astrojs/rss";
 import { getCollection } from "astro:content";
 import type { APIContext } from "astro";
+import sanitizeHtml from 'sanitize-html';
+import MarkdownIt from 'markdown-it';
+
+const parser = new MarkdownIt();
 
 export async function GET(context: APIContext) {
   const posts = await getCollection("posts");
@@ -13,6 +17,9 @@ export async function GET(context: APIContext) {
       .map((post) => ({
         title: post.data.title,
         description: post.data.description,
+        content: sanitizeHtml(parser.render(post.body), {
+          allowedTags: sanitizeHtml.defaults.allowedTags.concat(['img'])
+        }),
         author: post.data.author,
         pubDate: post.data.date,
         categories: [post.data.type],