Why is Sidescroll's Zoom Step marked private/static?

https://github.com/sebcrozet/kiss3d/blob/1b7819c4be4e19f8960a98d4a9229ab4964c40f8/src/planar_camera/sidescroll.rs#L17
Is private but doesn't have a function to change it.
Not intentional I presume.

Start with src/planar_camera/sidescroll.rs at line 17 and inspect the surrounding Sidescroll camera API to understand how Zoom Step is declared and used. Determine whether its visibility is intentional and whether the issue requires a public way to change it; done means the intended behavior is clear and reflected in the API.

Written by the indexing model from the issue text.