The ornamental design for a displayshelf, as shown and described.
FIG. 1 is a front perspective view of a display shelf showing my new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a left side elevation view thereof;
FIG. 4 is a right side elevation view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a front elevation view thereof;
FIG. 8 is a rear elevation view thereof; and,
FIG. 9 is a front perspective view of the display shelf of FIG. 1, in which each of the curved backdrops is provided with a graphical image in broken lines to illustrate an example.
The dashed broken lines in FIG. 9 are for environmental purposes only and form no part of the claimed design.