Add arduino to kit index page

Author: RealOrangeOne

docs/kit/index.md

@@ -4,8 +4,8 @@ title: Kit
 
 ## Boards
 
-Your kit consists of 4 main "boards":
+Your kit consists of 5 main "boards":
 
-| [Motor Board](./motor-board.md) | [Power Board](./power-board.md) | [Servo Board](./servo-board.md) | [Raspberry Pi](./pi.md) |
-|---|---|---|---|
-| ![Motor Board](../assets/img/kit/mcv4b.png) | ![Power Board](../assets/img/kit/pbv4.png) | ![Servo Board](../assets/img/kit/sbv4.png) | ![Pi](../assets/img/kit/pi.jpg) |
+| [Motor Board](./motor-board.md) | [Power Board](./power-board.md) | [Servo Board](./servo-board.md) | [Arduino](./arduino.md) | [Raspberry Pi](./pi.md) |
+|---|---|---|---|---|
+| ![Motor Board](../assets/img/kit/mcv4b.png) | ![Power Board](../assets/img/kit/pbv4.png) | ![Servo Board](../assets/img/kit/sbv4.png) | ![Arduino](../assets/img/kit/arduino_headers.png) | ![Pi](../assets/img/kit/pi.jpg) |