changed the SVG path for I2C diagram to be internal

Author: BartMassey

mdbook/src/11-i2c/the-general-protocol.md

@@ -8,7 +8,7 @@ communication between several devices. Let's see how it works using examples:
 If the Controller wants to send data to the Target:
 
 <p align="center">
-  <img class="white_bg" height="360" title="I2C bus" src="https://upload.wikimedia.org/wikipedia/commons/thumb/0/04/I2C_controller-target.svg/640px-I2C_controller-target.svg.png" />
+  <img class="white_bg" height="360" title="I2C bus" src="../assets/i2c-controller-target.svg" />
 </p>
 
 1. Controller: Broadcast START
@@ -27,7 +27,7 @@ If the Controller wants to send data to the Target:
 If the controller wants to read data from the target:
 
 <p align="center">
-<img class="white_bg" height="360" title="I2C bus" src="https://upload.wikimedia.org/wikipedia/commons/thumb/0/04/I2C_controller-target.svg/640px-I2C_controller-target.svg.png" />
+  <img class="white_bg" height="360" title="I2C bus" src="../assets/i2c-controller-target.svg" />
 </p>
 
 1. C: Broadcast START