Merge branch 'cherry-pick-85bba0a8' into 'releases/3.7'

Merge branch 'fix/satisfy-headercheck-cahn' into 'master'

See merge request !3516

examples/cahn_hilliard/doc/model.md

@@ -30,9 +30,11 @@ We start in `model.hh` with the necessary header includes:
 
 ```cpp
 
+#include <dune/common/fvector.hh>
 #include <dumux/common/math.hh>
 #include <dumux/common/properties.hh>
 #include <dumux/common/numeqvector.hh>
+#include <dumux/discretization/method.hh>
 ```
 
 </details>

examples/cahn_hilliard/model.hh

@@ -41,9 +41,11 @@
 //
 // We start in `model.hh` with the necessary header includes:
 // [[details]] includes
+#include <dune/common/fvector.hh>
 #include <dumux/common/math.hh>
 #include <dumux/common/properties.hh>
 #include <dumux/common/numeqvector.hh>
+#include <dumux/discretization/method.hh>
 // [[/details]]
 //
 // ## 1. Property Tag

examples/diffusion/doc/model.md

@@ -22,6 +22,7 @@ We start in `model.hh` with the necessary header includes:
 
 ```cpp
 
+#include <dune/common/fvector.hh>
 #include <dumux/common/math.hh>
 #include <dumux/common/properties.hh>
 #include <dumux/common/numeqvector.hh>

examples/diffusion/model.hh

@@ -32,6 +32,7 @@
 //
 // We start in `model.hh` with the necessary header includes:
 // [[details]] includes
+#include <dune/common/fvector.hh>
 #include <dumux/common/math.hh>
 #include <dumux/common/properties.hh>
 #include <dumux/common/numeqvector.hh>