add the patch

.patches/exercise-dunemodule/exercise-dunemodule.patch

 diff -ruN exercises/exercise-dunemodule/README.md exercises/solution/exercise-dunemodule/README.md
---- exercises/exercise-dunemodule/README.md	2024-07-15 15:50:06.499877396 +0200
+--- exercises/exercise-dunemodule/README.md	2024-07-16 15:24:17.152614242 +0200
 +++ exercises/solution/exercise-dunemodule/README.md	1970-01-01 01:00:00.000000000 +0100
 @@ -1,114 +0,0 @@
 -# Exercise New Dune Module (DuMuX course)
@@ -10,7 +10,7 @@ diff -ruN exercises/exercise-dunemodule/README.md exercises/solution/exercise-du
 -This is the suggested
 -workflow to develop code on top of DuMuX.
 -
--### Task 1: Create new dune module
+-## Task 1: Create new dune module
 -
 -* Execute the following command (bash environment) in the top-folder, i.e. above the dumux folder
 -
@@ -25,7 +25,7 @@ diff -ruN exercises/exercise-dunemodule/README.md exercises/solution/exercise-du
 -    * your email address
 -
 -
--### Task 2: Rerun dunecontrol to configure your new project
+-## Task 2: Rerun dunecontrol to configure your new project
 -
 -The following command will configure your new module
 -
@@ -35,7 +35,7 @@ diff -ruN exercises/exercise-dunemodule/README.md exercises/solution/exercise-du
 -
 -You need to run this command in the folder with content dumux, dumux-course, dune-common, dune-geometry, dune-grid, dune-istl, etc. `<module-name>` needs to be replaced (please replace the angle brackets also) by the name of the module, e.g., by `dumux-example`.
 -
--### Task 3: Create a new test case within your new DuMuX module
+-## Task 3: Create a new test case within your new DuMuX module
 -
 -* Create a new folder (in your module folder), e.g., `appl`
 -
@@ -78,7 +78,7 @@ diff -ruN exercises/exercise-dunemodule/README.md exercises/solution/exercise-du
 -```
 -
 -
--### Task 4: Create a new GitLab project
+-## Task 4: Create a new GitLab project
 -
 -
 -* Login with your username and password at https://git.iws.uni-stuttgart.de/