Update README.md

Deleted ROS_nodes/panda_capacity/launch/config.rviz, ROS_nodes/panda_capacity/launch/config_two.rviz, ROS_nodes/panda_capacity/launch/one_panda.launch, ROS_nodes/panda_capacity/launch/two_panda.launch, ROS_nodes/panda_capacity/scripts/capacity/init.py, ROS_nodes/panda_capacity/scripts/capacity/capacity_visual_utils.py, ROS_nodes/panda_capacity/scripts/capacity/robot_solver.py, ROS_nodes/panda_capacity/scripts/panda_force_polytope.py, ROS_nodes/panda_capacity/scripts/panda_force_polytope_intersection.py, ROS_nodes/panda_capacity/scripts/panda_force_polytope_sum.py, ROS_nodes/panda_capacity/scripts/panda_manipulability.py, ROS_nodes/panda_capacity/CMakeLists.txt, ROS_nodes/panda_capacity/package.xml, matlab_octave/J_panda.m, matlab_octave/J_ur5.m, matlab_octave/README.md, matlab_octave/octave-workspace, matlab_octave/panda_test_polytope_algorithms.m, matlab_octave/polytope_auctus.m, matlab_octave/polytope_pierrot.m, matlab_octave/polytope_sasaki.m, matlab_octave/ur5_test_polytope_algorithms.m, paper/ICRA2021.pdf files