Make config.description optional in atom.xml

components/templates/src/builtins/atom.xml

@@ -1,7 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <feed xmlns="http://www.w3.org/2005/Atom" xml:lang="{{ config.default_language }}">
 	<title>{{ config.title }}</title>
+	{%- if config.description %}
 	<subtitle>{{ config.description }}</subtitle>
+	{%- endif %}
 	<link href="{{ feed_url | safe }}" rel="self" type="application/atom+xml"/>
 	<link href="{{ config.base_url | safe }}"/>
 	<generator uri="https://www.getzola.org/">Zola</generator>