We claim the ornamental design for a digital signage, as shown and described.
FIG. 1 is a perspective view of a digital signage showing the new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a left-side elevation view thereof;
FIG. 5 is a right-side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines represent portions of the stand for digital signage that form no part of the claimed design. The dashed-dot lines are used to define boundaries of the claimed design and form no part thereof.