[Doc] add credits (#93)

Author: cagix

CREDITS.md

@@ -0,0 +1,44 @@
+# Credits
+
+This is a list of external projects used to build the lecture slides and the lecture
+notes for the teaching material. These are licensed under their own licences and are
+not part of the MIT licence of this project.
+
+
+## Building the Lecture Slides
+
+*   [Pandoc](https://github.com/jgm/pandoc)
+*   [Pandoc-Lecture](https://github.com/cagix/pandoc-lecture)
+*   [TeX Live](http://tug.org/texlive/)
+*   [Beamer](https://github.com/josephwright/beamer)
+*   [Metropolis](https://github.com/matze/mtheme)
+
+
+## Building the Lecture Web Pages
+
+*   Pre-processing:
+    *   [Pandoc](https://github.com/jgm/pandoc)
+    *   [Pandoc-Lecture](https://github.com/cagix/pandoc-lecture)
+*   Compilation of the lecture websites:
+    *   [Hugo](https://github.com/gohugoio/hugo)
+    *   [Hugo Relearn Theme](https://github.com/McShelby/hugo-theme-relearn)
+    *   [Pandoc-Lecture](https://github.com/cagix/pandoc-lecture/tree/master/hugo/hugo-lecture)
+*   These projects, among others, are used in the generated web pages:
+    *   Icons: [Font Awesome](https://fontawesome.com)
+    *   Rendering of mathematical formulas: [MathJax](https://www.mathjax.org/)
+
+
+## Further Tools used
+
+*   [GNU Make](https://www.gnu.org/software/make/)
+*   [Pandoc Dockerfiles](https://github.com/pandoc/dockerfiles)
+*   [Docker](https://www.docker.com/)
+*   [GitHub](https://github.com/)
+
+
+## Contributors
+
+[This project](https://github.com/cagix/pandoc-lecture)
+has been created and is being maintained by the author
+[Carsten Gips](https://github.com/cagix) and various
+[contributors](https://github.com/cagix/pandoc-lecture/graphs/contributors).

README.md

@@ -265,6 +265,11 @@ Please first check whether your request has already been dealt with in other (op
 When submitting pull requests, please make sure that your **feature branch starts at the tip of the current `master` branch**. Upon acceptance (i.e. merging your pull request), your contribution automatically becomes subject to the licence of this repository (MIT).
 
 
+## Credits
+
+See the [credits](CREDITS.md) for a detailed list of contributing projects.
+
+
 ---
 
 # License