feat: add article categories to RSS

Signed-off-by: Filipe Medeiros <hello@filipesm.eu>

lib/generateRssFeed.tsx

@@ -56,6 +56,9 @@ export default async function generateRssFeed() {
         description: richTextAsPlainText(
           blogPost.properties.Description.rich_text,
         ),
+        category: blogPost.properties.Topics.multi_select.map(({ name }) => ({
+          name,
+        })),
         contributor: [author],
         content: html,
         date: new Date(