If showInSidebar is set to false for child pages, hide card/content from parent pages

## What New Or Updated Would You Like To See?

When `showInSidebar: false` is used to hide content from the left-hand navigation sidebar, the cards/content still appear on the parent pages. We would like to be able to hide this content from the parent pages as well.

## Why Is It Needed?

Currently, if content is hidden from the left-hand navigation sidebar, it is still visible on the parent page. This was noticed when the Support team was rewriting the organizational guide.

## Additional Context?

None at this time, but happy to add additional context as requested.