tutorial update

some minor fixes in the pull request.

open issues:
- I am missing some more details in the overview what the user is going to do in the tutorial (e.g. develop driver and testing node, generate communication hull, maybe list the API here, create a system model and deploy it)
- robot description is a parameter not a file --> update screenshot
- input and output ports are not clearly separated (input should be on left side, output on right side)