Include newgrp - docker instead of sudo (#1305)

While launching adb shell, we should launch newgrp - docker command instead of sudo

Author: martab1994

content/hardware/04.pro/boards/portenta-x8/tutorials/05.docker-container/content.md

@@ -53,7 +53,7 @@ You can check Docker's reference documentation, which covers all the features of
 
 The following steps will show how to install, run and uninstall the "Hello World" container.
 
-To avoid a lack of permissions while running the Docker's commands, you may need to run the next command to gain admin (root) access: ```sudo su -``` , which default password is ```fio```
+To avoid a lack of permissions while launching ```adb shell```, you may type the following: ```newgrp - docker```.
 
 The previous command and other important info about Linux on your Portenta are described in the [Portenta X8 User Manual](https://docs.arduino.cc/tutorials/portenta-x8/user-manual#working-with-linux).
 
@@ -137,4 +137,4 @@ In this tutorial, you have learned how to use Docker with Portenta X8. You have
 
 - Now that you have the base of the workflow to use [Docker](https://docker.com), go to its docs page and make sure you understand all the features.
 - Look for a container image from [Docker hub](http://hub.docker.com), install it and make your own application out of it.
-- Create a container to run your custom-made application. For this, it may interest you [Deploy a Custom Container with Portenta X8 Manager](https://docs.arduino.cc/tutorials/portenta-x8/custom-container) tutorial.
+- Create a container to run your custom-made application. For this, it may interest you [Deploy a Custom Container with Portenta X8 Manager](https://docs.arduino.cc/tutorials/portenta-x8/custom-container) tutorial.