修复左侧目录没有折叠的问题

book.toml

@@ -11,4 +11,8 @@ git-repository-icon = "fa-git"
 
 additional-js = ["theme/myjs/mermaid.min.js", "theme/myjs/mermaid-init.js","theme/myjs/jquery-1.12.3.min.js","theme/myjs/lrc.js","theme/myjs/nosleep.js","theme/myjs/social-share.min.js","theme/myplugin/layer/layer.js","theme/myplugin/pagetoc/sidebar.js"]
 mathjax-support = true
-additional-css = ["theme/fonts/tai-tham-kh-new-v3.ttf","theme/mycss/font.css","theme/mycss/lrc.css","theme/mycss/share.min.css","theme/fonts/iconfont.ttf","theme/fonts/iconfont.woff","theme/myplugin/layer/theme/default/layer.css","theme/myplugin/layer/theme/default/icon.png","theme/myplugin/pagetoc/style.css"] 
+additional-css = ["theme/fonts/tai-tham-kh-new-v3.ttf","theme/mycss/font.css","theme/mycss/lrc.css","theme/mycss/share.min.css","theme/fonts/iconfont.ttf","theme/fonts/iconfont.woff","theme/myplugin/layer/theme/default/layer.css","theme/myplugin/layer/theme/default/icon.png","theme/myplugin/pagetoc/style.css"] 
+
+[output.html.fold]
+enable = true
+level = 0