Feature/ci slides setup

slides/README.md

-# DuMu<sup>x</sup> course slides
+# DuMuX course slides
 
-Click on the links to download the slides
-
-* [Slides on the basics](./dumux-course-intro.pdf)
-* [Slides on the problem file](./dumux-course-problem.pdf)
-* [Slides on runtime parameters and grids](./dumux-course-runtimeparams-grids.pdf)
-* [Slides on properties](./dumux-course-properties.pdf)
-* [Slides on the material system](./dumux-course-materialsystem.pdf)
-* [Introduction to multidomain framework](./dumux-course-multidomain.pdf), or view it online [here](https://pages.iws.uni-stuttgart.de/dumux-repositories/dumux-course/)
-* [Slides on coupling free and porous medium flow (SFB PA A)](./dumux-course-coupling-ff-pm.pdf)
-* [Slides on discrete fracture modelling exercise (SFB PA B)](http://dumux-repositories.pages.iws.uni-stuttgart.de/dumux-course-orga/pa02_presentation.html)
-* [Slides on biomineralization (SFB PA C)](./dumux-course-biomin.pdf)
+The slides are automatically built and deployed in the CI and can be viewed at
+[pages.iws.uni-stuttgart.de/dumux-repositories/dumux-course/](https://pages.iws.uni-stuttgart.de/dumux-repositories/dumux-course/index.html).
+In order to add new slides, simply add your `.md` file in this folder, and add
+an entry to `index.md` such that your slides are linked from the landing page.
+__Important__: make sure to put your `.md` at the right position in the list.