update README

Author: AtsushiSakai

README.md

@@ -156,6 +156,13 @@ Path tracking simulation with rear wheel feedback steering control and PID speed
 
 ![PythonRobotics/figure_1.png at master · AtsushiSakai/PythonRobotics](https://github.com/AtsushiSakai/PythonRobotics/blob/master/PathTracking/rear_wheel_feedback/animation.gif)
 
+## Linear–quadratic regulator (LQR) control
+
+Path tracking simulation with LQR steering control and PID speed control.
+
+![PythonRobotics/figure_1.png at master · AtsushiSakai/PythonRobotics](https://github.com/AtsushiSakai/PythonRobotics/blob/master/PathTracking/LQR/animation.gif)
+
+
 # License 
 
 MIT