Create the top header used in boxed layout. This function accepts raw `li` items (created by `menu_item`) or a `sidebar_brand()` attached as `title` attribute on a `ul`.
navbar_menu(..., brand = NULL, show_theme_button = FALSE)An HTML tag for the header
Additional nodes to include (typically `menu_item()` elements)
Optional brand for the navbar; either a string (text title), `sidebar_brand(...)` or a named list with elements `text` and `img` (URL/path).
Whether to show the theme toggle buttons (default: `FALSE``).