Resolve "Follow-up from "Resolve "Implement image flip service"""

What does this MR do?

• Update the documentation of Tuto06Filter, after the recent addition of https://git.ircad.fr/Sight/sight/merge_requests/88 (new SFlip service)

Closes #22 (closed)

How to test it?

• Build the documentation and ensure that there are no errors

Associated Issues/Merge Requests

• Merge requests
  • https://git.ircad.fr/Sight/sight/merge_requests/88