message: Fix UnstructMeshField example in Slam
diff: @@ -74,8 +74,8 @@ public:
  /// types for maps
  using BaseSet = axom::slam::Set<PositionType, ElementType>;
  - using NodalPositions = slam::Map<Point>;
  - using ZonalPositions = slam::Map<Point>;
  + using NodalPositions = slam::Map<Point3>;
  + using ZonalPositions = slam::Map<Point3>;
  using NodeField = slam::Map<DataType>;
  using ZoneField = slam::Map<DataType>;
  