Update 7 files

- /_includes/word_count.html
- /_config.yml
- /_layouts/default.html
- /Gemfile
- /js/rss-feed-preview.js
- /_posts/2025-04-08-feed.md
- /links.md

Gemfile

@@ -6,6 +6,7 @@ group :jekyll_plugins do
   gem "jekyll-assets", "~> 1.0.0"
   gem "jekyll-sitemap", "~> 1.4.0"
   gem "jekyll-feed", "~> 0.15.1"
+  gem "jekyll-include-cache", "~> 0.2.1"
   gem "jekyll-theme-minimal"
   gem "jekyll-paginate", "~> 1.1.0"
   gem "kramdown-parser-gfm", "~> 1.1.0"