The ornamental design for a satchel, as shown and described.
FIG. 1 is a rear and left-side isometric view of a satchel in accordance with the present design;
FIG. 2 is a rear elevational view of the satchel of FIG. 1;
FIG. 3 is a front elevational view of the satchel of FIG. 1;
FIG. 4 is a right side elevational view of the satchel of FIG. 1;
FIG. 5 is a left side elevational view of the satchel of FIG. 1;
FIG. 6 is a top plan view of the satchel of FIG. 1;
FIG. 7 is a bottom plan view of the satchel of FIG. 1; and,
FIG. 8 is a rear and left-side isometric view of the satchel of FIG. 1, showing how the satchel may be worn by an adult human.
The broken lines, including the less-prominent broken lines representing stitching, are included for purposes of illustrating environment and form no part of the claimed design.