Add category tag to RSS feed (#534)

Co-authored-by: ekzyis <ek@stacker.news>

lib/rss.js

@@ -23,6 +23,7 @@ const generateRssItem = (item) => {
   if (item.isJob) {
     title = item.title + ' \\ ' + item.company + ' \\ ' + `${item.location || ''}${item.location && item.remote ? ' or ' : ''}${item.remote ? 'Remote' : ''}`
   }
+  const category = item.subName ? `<category domain="${SITE_URL}/~${item.subName}">${item.subName}</category>` : '<category></category>'
   return `
     <item>
       <guid>${guid}</guid>
@@ -31,6 +32,7 @@ const generateRssItem = (item) => {
       <comments>${guid}</comments>
       <description><![CDATA[<a href="${guid}">Comments</a>]]></description>
       <pubDate>${new Date(item.createdAt).toUTCString()}</pubDate>
+      ${category}
       <atom:author><atom:name>${item.user.name}</atom:name></atom:author>
     </item>
   `