Bug-fix: cd into mounted volume in docker container (#1423)

Author: MaxPayne86

content/hardware/04.pro/boards/portenta-x8/tutorials/08.image-building/content.md

@@ -99,7 +99,7 @@ git config --global user.name "Your Name"
 Change to the home directory, and initialize the repository using **repo**:
 
 ```
-cd ~
+cd /dockerVolume
 repo init -u https://github.com/arduino/lmp-manifest.git -m arduino.xml -b release
 ```
 
@@ -236,4 +236,4 @@ Please follow the [Flashing tutorial](image-flashing) to flash your device with
 
 ## Troubleshooting
 
-- If you are having `do_fetch` issues, try to check your system's and virtual machine's DNS settings.
+- If you are having `do_fetch` issues, try to check your system's and virtual machine's DNS settings.