Doorbell

FIG. 1 is a front perspective view of a doorbell showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left-side elevational view thereof;

FIG. 5 is a right-side elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The dot-dash lines depict a boundary line of the doorbell and form no part of the claimed design. The dash-dash broken lines depict portions of the doorbell that form no part of the claimed design.