fix(blog): Fix homepage link in RSS feed

When following the Node.js Blog at https://nodejs.org/en/blog in a feed reader
like NetNewsWire, the homepage link gets broken. Instead of navigating the
browser to the website, one gets a blank page and an unexpected RSS feed
download in the background.

The `<link>` tag in RSS 2.0 is for the HTML website. Note that the
"self" link from the RSS file back to itself is separate form this
and already auto-generated by the Feed class. [1]

While at it, fix the broken `<description>undefined</defined>` element.
This is often left empty and fine not to pass in `/apps/site/site.json`.
However, the upstream Feed class has a bug where it takes the undefined
and outputs the string "undefined" as the blog's description instead
of a sensible default like empty string.

[1]: https://github.com/jpmonette/feed

Signed-off-by: Timo Tijhof <krinkle@fastmail.com>

Author: Krinkle

apps/site/next-data/generators/__tests__/websiteFeeds.test.mjs

@@ -30,8 +30,8 @@ describe('generateWebsiteFeeds', () => {
       id: siteConfig.rssFeeds[0].file,
       title: siteConfig.rssFeeds[0].title,
       language: 'en',
-      link: `${base}/feed/${siteConfig.rssFeeds[0].file}`,
-      description: siteConfig.rssFeeds[0].description,
+      link: base,
+      description: siteConfig.rssFeeds[0].description || '',
     });
 
     const date = new Date(blogData.posts[0].date);

apps/site/next-data/generators/websiteFeeds.mjs

@@ -32,8 +32,8 @@ const generateWebsiteFeeds = ({ posts }) => {
         id: file,
         title: title,
         language: 'en',
-        link: `${canonicalUrl}/feed/${file}`,
-        description: description,
+        link: canonicalUrl,
+        description: description || '',
       });
 
       const blogFeedEntries = posts