Merge branch 'docu/update-readme-examples' into 'master'

[examples][docu] Update README.md with correct path to shallowwater example

See merge request !1737

examples/README.md

@@ -3,5 +3,5 @@ Examples
 The following resources are useful to get started with DuMux:
 
 * [1ptracer](https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/tree/master/examples/1ptracer),
-* [2pinfiltration](https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/tree/master/examples/2pinfiltration).
-* [shallowwater](https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/tree/master/examples/shallowwater).
+* [2pinfiltration](https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/tree/master/examples/2pinfiltration),
+* [shallowwaterfriction](https://git.iws.uni-stuttgart.de/dumux-repositories/dumux/tree/master/examples/shallowwaterfriction).