Tutorial slides

I never saw them being referenced and I am not sure if they are important, but in the current state the tutorial cannot be viewed due to CSP conflicts as the page contains an inline script tag (violating the script-src directive). It also is clearly part of the frontend and should be moved to a frontend react router page if it is still required. The current architecture is weird and should be modified (e.g. https://exams.vis.ethz.ch/tutorial/demo.html which is just the reveal.js demo).