Add DUNE in the list of perpendicular-flap case solvers

Author: MakisH

perpendicular-flap/README.md

@@ -35,6 +35,8 @@ Solid participant:
 
 * deal.II. This tutorial works only with `Model = linear` since the deal.II codes were developed with read data `Stress` instead of `Force` as applied here (example given in Turek-Hron-FSI) in the first place. The `./run.sh` script takes the compiled executable `elasticity` as input argument (`run.sh -e=/path/to/elasticity`) and is required in case the executable is not discoverable at runtime (e.g. has been added to the system `PATH`). For more information, have a look at the [deal.II adapter documentation](https://www.precice.org/adapter-dealii-overview.html).
 
+* DUNE. For more information, have a look at the [experimental DUNE adapter](https://github.com/precice/dune-adapter) and send us your feedback.
+
 ## Running the Simulation
 
 All listed solvers can be used in order to run the simulation. OpenFOAM can be executed in parallel using `run.sh -parallel`. The default setting uses 4 MPI ranks. Open two separate terminals and start the desired fluid and solid participant by calling the respective run script `run.sh` located in the participant directory. For example: