Assistant: Third iteration of steps

After the router of the assistant, and the overview of the process, come the precise steps. Those will incorporate our existing documentation and refresh it. This task is meant to prepare all the needed content, starting with a example scenario (Windows USB) and then completing the others.

Parent Task: #8588 (closed)

Subtasks

#9200 (closed)
#9201 (closed)
#9202 (closed)

Original created by @sajolida on 9199 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information