Add config option to control child page limit

userguide/content/en/docs/adding-content/navigation.md

@@ -219,7 +219,7 @@ description: >
 
 By default, the section menu shows the current section fully expanded all the way down. This may make the left nav too long and difficult to scan for bigger sites. Try setting site parameter `ui.sidebar_menu_compact = true` in `config.toml`.
 
-With the compact menu (`.ui.sidebar_menu_compact = true`), only the current page's ancestors, siblings and direct descendants are shown. You can use the optional parameter `.ui.ul_show` to set a desired menu depth to always be visible. For example, with `.ui.ul_show = 1` the first menu level is always displayed.
+With the compact menu (`.ui.sidebar_menu_compact = true`), only the current page's ancestors, siblings and direct descendants are shown. You can use the optional parameter `.ui.ul_show` to set a desired menu depth to always be visible. For example, with `.ui.ul_show = 1` the first menu level is always displayed. The number of child pages shown per parent can be controlled using `sidebar_menu_truncate` (default: 50).
 
 As well as the completely expanded and compact menu options, you can also create a foldable menu by setting the site parameter `ui.sidebar_menu_foldable = true` in `config.toml`. The foldable menu lets users expand and collapse menu sections by toggling arrow icons beside the section parents in the menu.