message: move createSnapGrid to InteractStatic
  move createSnapGrid to InteractStatic
diff: @@ -288,6 +288,7 @@ declare namespace interact {
  supportsPointerEvent () : boolean
  stop ( event: any ) : InteractStatic
  pointerMoveTolerance ( tol?: number ) : number | InteractStatic
  + createSnapGrid ( opt: { x: number, y: number } ) : SnapFunction
  // TODO
  isSet ( any ) : any
  off ( any ) : any
  