Update directories in preparing_inputs.md
Update directories in preparing_inputs.md

xcyan/models,cshallue/models,xcyan/models,jch1/models,xcyan/models,xcyan/models,tombstone/models,alexgorban/models,xcyan/models,jiaphuan/models,jch1/models,sshleifer/object_detection_kitti,tombstone/models,derekjchow/models,jch1/models,alexgorban/models,sshleifer/object_detection_kitti,tombstone/models,tombstone/models,derekjchow/models,derekjchow/models,jiaphuan/models,sshleifer/object_detection_kitti,jch1/models,cshallue/models,derekjchow/models,tombstone/models,sshleifer/object_detection_kitti,sshleifer/object_detection_kitti,cshallue/models,jiaphuan/models,alexgorban/models,derekjchow/models,cshallue/models,alexgorban/models,cshallue/models,jiaphuan/models,jiaphuan/models,alexgorban/models,zbigniewwojna/text-rcnn,jch1/models,jch1/models,xcyan/models,jiaphuan/models,sshleifer/object_detection_kitti,tombstone/models