$pagePicker->start()
Calculates the top-most model (page or site) that can be accessed when navigating through pages.
$pagePicker->start(): Kirby\Cms\Page|Kirby\Cms\Site
Return types
Kirby\Cms\Page
orKirby\Cms\Site
This method modifies the existing $pagepicker
object it is applied to and returns it again.