Add control game to TOC

Author: alchemyst

TOC.ipynb

@@ -125,6 +125,7 @@
     "# 2. Control\n",
     "\n",
     "## 2.1 Conventional feedback control\n",
+    "* [Control game](2_Control/1_Conventional_feedback_control/Control%20game.ipynb)\n",
     "* [PID controller step responses](2_Control/1_Conventional_feedback_control/PID%20controller%20step%20responses.ipynb)\n",
     "* [Effect of Proportional Control](2_Control/1_Conventional_feedback_control/Effect%20of%20Proportional%20Control.ipynb)\n",
     "* [PID control on TCLab](tclab/TCLab%20PID.ipynb)\n",