to avoid a dependency to https://github.com/stack-of-tasks/talos-data/
in many packages

edit: fix meshes with meshlab

from https://github.com/open-dynamic-robot-initiative/open_robot_actuator_hardware/tree/master/mechanics/quadruped_robot_8dof_v1/stl_files_for_visualization

* Added quadcopter Iris from 3DRobotics

* [readme] add hector and iris to the launch command

* [iris] Added reduced version of the STL file

Co-authored-by: PepMS <jmarti@iri.upc.edu>

robots/talos_data/urdf/talos_reduced.urdf is also available at
robots/talos_data/robots/talos_reduced.urdf

Thanks @nmansard for the repport.

To not trigger Pinocchio's SO(2) representation