The ornamental design for a babyshirt with a detachable bib, as shown and described.
FIG. 1 is a top, front, left side perspective view of the baby shirt and detachable bib, with broken lines illustrating being worn by a child as environmental structure;
FIG. 2 is a top, front, left side perspective view of the baby shirt and detachable bib;
FIG. 3 is a front elevation view of the baby shirt and detachable bib of FIG. 2;
FIG. 4 is an exploded perspective view of the baby shirt and removeable bib portions; and,
FIG. 5 is a rear elevation view of the detachable bib portion.
In the drawings, the broken lines and stitching are for the purposes of illustrating environment only, and form no part of the claimed design.