Enable foldable sidebar menu (#31818)

* (feat: sidebar) enable sidebar menu foldable

* (feat: sidebar) add comment for params

* fix comment format

Co-authored-by: championshuttler <[email protected]>

Co-authored-by: championshuttler <[email protected]>

Author: FOWind

config.toml

@@ -217,6 +217,8 @@ url = "https://v1-20.docs.kubernetes.io"
 [params.ui]
 # Enable to show the side bar menu in its compact state.
 sidebar_menu_compact = false
+# Show expand/collapse icon for sidebar sections.
+sidebar_menu_foldable = true
 # https://github.com/gohugoio/hugo/issues/8918#issuecomment-903314696
 sidebar_cache_limit = 1
 #  Set to true to disable breadcrumb navigation.