lat/lon are required: this type is for points the map can actually
focus on. A slide may carry a location without coordinates (an image
region, an icon only) — that is StorymapSlideLocation, which keeps them
optional. lng is accepted as a legacy alias on input only.
A resolved geographic coordinate.
lat/lonare required: this type is for points the map can actually focus on. A slide may carry alocationwithout coordinates (an image region, an icon only) — that isStorymapSlideLocation, which keeps them optional.lngis accepted as a legacy alias on input only.