Update mkdocs.yml

Ankle FSM docs included in the nav

Author: matteo-crotti

mkdocs.yml

@@ -46,6 +46,7 @@ nav:
   - Examples:
       - Basic Motion: examples/basic_motion.md
       - Finite State Machine Walking Controller: examples/fsm_walking_controller.md
+      - FSM Walking Ankle Controller: examples/fsm_walking_ankle_controller.md
   - API:
       - Actuators:
           - Base: api/actuators/actuators.md