The implementation puts the minzoom for `highway=service` at [14](https://github.com/geofabrik/shortbread-tilemaker/blob/main/process.lua#L668-L670), the specs says 13. Also splitting the `elseif`s for zoom level 13 [here](https://github.com/geofabrik/shortbread-tilemaker/blob/main/process.lua#L665-L667) and [here](https://github.com/geofabrik/shortbread-tilemaker/blob/main/process.lua#L671-L673) seems strange.
