The README is a work in progress and I'm working to have a complete set of documentation soon.
Regarding elevation: All coordinates may have an optional 'z' member. For example, you can add a simple point `set garden tomatoes point 33.5091 -112.7998 125` which would create a point with 'z' equal to 125. Or, you could have a complex GeoJSON object containing multiple coordinates or features. There's no limits to this values except that it must be a number.
At this time the only supported coordinate system is WGS84. Though I'm open to suggestions.
