The ornamental design for a gameboard, as shown and described.
FIG. 1 is a top plan view of a first embodiment of a game board embodying our new design; and
FIG. 2 is a top plan view of a second embodiment of a game board embodying our new design; and,
FIG. 3 is a top plan view of a third embodiment of a game board embodying our new design.
In FIG. 2, the symbol in broken lines inside each circle in the circular game path, and the perimeter in broken lines of each corner rectangle, and the symbol in broken lines inside each corner rectangular form no part of the claimed design. In FIG. 3, the spinner in broken lines forms no part of the claimed design. The game board is printed on a flat surface and therefore, the front view, the rear view, the left side view, the right side view, and the bottom view form no part of the claimed subject matter.