✨ feat(sitemap): add XML styling (#221)

templates/sitemap.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<?xml-stylesheet href="{{ get_url(path='/sitemap_style.xsl', trailing_slash=false) | safe }}" type="text/xsl"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+    {%- for sitemap_entry in entries %}
+    <url>
+        <loc>{{ sitemap_entry.permalink | escape_xml | safe }}</loc>
+        {%- if sitemap_entry.updated %}
+        <lastmod>{{ sitemap_entry.updated }}</lastmod>
+        {%- endif %}
+    </url>
+    {%- endfor %}
+</urlset>