sidebar on home page does not have expected behaviour

[stevejpurves]

Shown here 👇 on the home page, we expect the sidebar to grey out background content as on any other page, with consistent click actions, but that is not the case.

The issue may be in the [Configurable]PrimaryNavigation component in myst-theme where the logic for hiding the background screening div is incorrect.

This is discussed in #12.