Fix baseUrl on rss-feed (cotes2020#259)

Author: cotes2020

feed.xml

@@ -9,23 +9,24 @@ layout: compress
 
 {% capture source %}
 <feed xmlns="http://www.w3.org/2005/Atom">
-  <id>{{ site.url }}</id>
+  <id>{{ "/" | absolute_url }}</id>
   <title>{{ site.title }}</title>
   <subtitle>{{ site.description }}</subtitle>
   <updated>{{ site.time | date_to_xmlschema }}</updated>
   <author>
     <name>{{ site.author }}</name>
-    <uri>{{ site.url }}</uri>
+    <uri>{{ "/" | absolute_url }}</uri>
   </author>
-  <link href="/feed.xml" rel="self" type="application/atom+xml" />
-  <link href="{{ site.url }}" rel="alternate" type="text/html" />
+  <link rel="self" type="application/atom+xml" href="{{ page.url | absolute_url }}"/>
+  <link rel="alternate" type="text/html" hreflang="{{ site.lang | default: 'en' }}"
+    href="{{ '/' | absolute_url }}"/>
   <generator uri="https://jekyllrb.com/" version="{{ jekyll.version }}">Jekyll</generator>
   <rights> © {{ 'now' | date: '%Y' }} {{ site.author }} </rights>
   <icon>{{ site.baseurl }}/assets/img/favicons/favicon.ico</icon>
   <logo>{{ site.baseurl }}/assets/img/favicons/favicon-96x96.png</logo>
 
 {% for post in site.posts limit: 5 %}
-  {% assign post_absolute_url = site.url | append: post.url %}
+  {% assign post_absolute_url = post.url | absolute_url %}
   <entry>
     <title>{{ post.title }}</title>
     <link href="{{ post_absolute_url }}" rel="alternate" type="text/html" title="{{ post.title }}" />