Creates a polygon, with the given array of coordinates in  in format 
 [lng, lat].
        
        
- Source:
Example
//From https://developers.google.com/maps/documentation/javascript/examples/polygon-simple
 const myPolygon =   polygonFactory([
     [-80.190, 25.774], 
     [-66.118, 18.466],
     [-64.757, 32.321],
     [-80.190, 25.774]
 ]);
 let {
     lat, 
     lng
 } = myPolygon.getPolygonCenter();
 consle.log(`Center is: ${lat}, ${lng}`);
     
 myPolygon.getCoordinates().forEach(elem => {
     console.log(`Coord is ${elem.lat}, ${elem.lng}`); 
 });      
        
    
    Methods
- 
    <inner> getCoordinates()
- 
    
    Returns the array of coordinates of this polygon. It is calculated only once during the polygon's creation.- Source:
 Returns:The array of coordinates from the polygon.- Type
- Array
 
- 
    <inner> getPolygonCenter()
- 
    
    Returns the center coordinate of this polygon. It is calculated only once during the polygon's creation.- Source:
 Returns:The coordinate that represents the geometric center of the polygon.- Type
- Coordinate