Fix urdf files and add 2dof simulation with the simple robot

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

ros2_ws/src/simple_robot_1dof/urdf/simple_robot.urdf

...ple_robot_2dof/launch/kuka_rviz_simulation_2dof_launch.py

..._2dof/simple_robot_2dof/forward_kinematics_node_2dof_1.py

ros2_ws/src/simple_robot_2dof/urdf/simple_robot.urdf

...matik/simple_robot_inverse_kinematik/inverse_kinematik.py