* Add inverted_pendulum_lqr_control
* reorganize document of inverted pendulum control module
* Refactor inverted_pendulum_lqr_control.py
* Add doccument for inverted pendulum control
* Corrected inverted pedulum LQR control doccument
* Refactor inverted pendulum control by mpc and lqr
* Add unit test for inverted_pendulum_lqr_control.py