This is a regular content page, with content placed in the right sidebar.
The right sidebar content is defined in the content file, and in this case is provided by shortcodes.
Usage
The content file looks something like this:
---
title: Content page with right sidebar
layout: content-page
---
{{< main >}}
Main content goes hereā¦
{{< /main >}}
{{< sidebar right>}}
{{< sidebar/widget/on-this-page >}}
{{< /sidebar >}}