Update 8 files

- /_layouts/default.html
- /_includes/live2d.html
- /rss.xml
- /search.json
- /opensearch.xml
- /index.html
- /feed.json
- /404.md

rss.xml

@@ -1,5 +1,6 @@
 ---
 ---
+
 <?xml version="1.0" encoding="UTF-8"?>
 <?xml-stylesheet type="text/xml" href="/feed.xslt.xml"?>
 <rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom">