The LSST-DESC 3x2pt tomography optimization challenge by Zuntz, J, Lanusse, F, Malz, AI, Wright, AH, Slosar, A, Abolfathi, B, Alonso, D, Bault, A, Bom, CR, Brescia, M, Broussard, A, Campagne, J-E, Cavuoti, S, Cypriano, ES, Fraga, BMO, Gawiser, E, Gonzalez, EJ, Green, D, Hatfield, P, Iyer, K, Kirkby, D, Nicola, A, Nourbakhsh, E, Park, A, Teixeira, G, Heitmann, K, Kovacs, E, Mao, Y-Y