Update 2 files

- /Gemfile
- /_posts/2025-06-02-optimize.md

Gemfile

@@ -8,6 +8,7 @@ group :jekyll_plugins do
   gem "jekyll-feed", "~> 0.15.1"
   gem "jekyll-include-cache", "~> 0.2.1"
   gem "jekyll-readme-index", "~> 0.3.0"
+  gem "jekyll-default-layout", "~> 0.1.5"
   gem "jekyll-theme-minimal"
   gem "jekyll-paginate", "~> 1.1.0"
   gem "kramdown-parser-gfm", "~> 1.1.0"