Add matthias.endler.de to list of examples

EXAMPLES.md

@@ -18,3 +18,4 @@
 | [Tinkering](https://tinkering.xyz)                                 |                                                      |
 | [Daniel Sockwell's codesections.com](https://www.codesections.com) | https://gitlab.com/codesections/codesections-website |
 | [Jens Getreu's blog](https://blog.getreu.net)                      |                                                      |
+| [Matthias Endler](https://matthias-endler.de)                      | https://github.com/mre/mre.github.io                 |