Add ExaDG as thirdparty adapter (#163)

pages/docs/adapters/adapter-overview.md

@@ -33,6 +33,7 @@ Wherever meaningful (license, maturity of the project, no other home), we host t
 | [DuMuX](https://dumux.org/) | [Alexander Jaust, University of Stuttgart](https://www.ipvs.uni-stuttgart.de/institute/team/Jaust-00001/) | [code](https://git.iws.uni-stuttgart.de/dumux-appl/dumux-precice) | Free flow and porous-medium flow | Currently only coupled DuMuX to DuMuX. Feedback appreciated. |
 | [DUNE](https://dune-project.org/) | [Max Firmbach, UniBW M](https://www.unibw.de/imcs/team/firmbach) | [Thesis](https://mediatum.ub.tum.de/node?id=1609293), [code](https://github.com/precice/dune-adapter) | Structure part in FSI | |
 | [Elmer FEM](www.elmerfem.org) | [Benjamin Rodenberg, TUM](https://www.in.tum.de/i05/personen/personen/benjamin-rodenberg/) | [Thesis](https://mediatum.ub.tum.de/node?id=1636717), [code](https://github.com/precice/elmer-adapter) | Structure part in CHT, FSI, any FEM | looking for maintainers! |
+| [ExaDG](https://github.com/exadg/exadg) | [David Schneider, US](https://www.ipvs.uni-stuttgart.de/institute/team/Schneider-00056/) | [code](https://github.com/exadg/exadg/tree/master/applications/fluid_structure_interaction/perpendicular_flap) | Fluid or Structure part in FSI | |
 | [FASTEST](https://www.fnb.tu-darmstadt.de/forschung_fnb/software_fnb/software_fnb.en.jsp) | [TU Darmstadt FNB](https://www.fnb.tu-darmstadt.de/) | None | Fluid-Structure-Acoustics interaction | |
 | [FEAP](http://projects.ce.berkeley.edu/feap/) | [TU Darmstadt FNB](https://www.fnb.tu-darmstadt.de/) | None | Structure part in FSI | |
 | [FEniCS-X](https://fenicsproject.org/) | [Benjamin Rodenberg, TUM](https://www.in.tum.de/i05/personen/personen/benjamin-rodenberg/) | [code](https://github.com/precice/fenicsx-adapter) | Structure part in CHT, FSI, any FEM | looking for maintainers! |