Report on pages not in nav

While some pages are not in the left nav on purpose, most of the time it's accidental.

It would be nice to generate a report of pages not in the nav and to distribute that information more widely to the team, so each writer could check their area.

We could do this:

• As a report sent to slack?
• As an issue the whole team is assigned to?
• Any other ideas?

I thought of asking it to be added to the monthly chores, but I think this is more of a team-wide responsibility.