Add CI with build process

[levino]

The current setup is quite original, but also a bit unique: The PDF files are built with latex from .csv-files which often are not really CSV files but latex files (I guess?). Also the PDF output files are committed to master (which could be renamed to main which is considered less offensive by some these days) so the developers have to build and add the files to the commits, when they change the .csv files content (in order to fix a typo or whatever). I think there is room for improvement here, if anybody wants to do the work.

As a first step, I would remove all the PDF files from version control and only create them when preparing the website deployment. One could use github-pages-action to run the scripts in CI and deploy the GitHub page. Leveraging AI a bit, this task should not be too much work. I could do it, if the maintainers think it is a good idea to implement it. Let me know please.