Improve launch files and 2dof simulation

...wa_bringup/launch/__pycache__/iiwa.launch.cpython-310.pyc

...imple_robot_1dof/simple_robot_1dof/reference_node_1dof.py

...ple_robot_2dof/launch/kuka_rviz_simulation_2dof_launch.py

...f/launch/kuka_rviz_simulation_2dof_simultaneous_launch.py

ros2_ws/src/simple_robot_2dof/setup.py

..._2dof/simple_robot_2dof/forward_kinematics_node_2dof_1.py

..._2dof/simple_robot_2dof/forward_kinematics_node_2dof_2.py

...imple_robot_2dof/simple_robot_2dof/reference_node_2dof.py