docs(): stanley controller documentation

Author: mohitk3000

doc/DESIGN_DOCUMENT.md

@@ -5,4 +5,4 @@ This document provides an explanation of each Python programs design in this rep
 1. [World Visualization](/doc/1_world_visualization/1_world_visualization.md)
 2. [Vehicle Model](/doc/2_vehicle_model/2_vehicle_model.md)
 3. [Sensor Models](/doc/3_sensor_models/3_sensor_models.md)
-4. [Path Tracking] (/doc/4_path_tracking/4_staley_controller.md)
+4. [Path Tracking](/doc/4_path_tracking/4_staley_controller.md)