Each idea in your rookery gets its own page. By default, it shows the idea’s title and ID, its body, and the context and backlinks footer. You can set a template for it—to add a site header and footer, for example—like so:
#let idea-page-template(id: none, note: (:), doc) = {
show: chrome.with(current-page: id)
doc
}
#show: rookery.with(
idea-page-template: idea-page-template,
)