fixes Doxygen documentation

src/utils/read_icon_grid.h

@@ -6,13 +6,21 @@
 
 // YAC PUBLIC HEADER START
 
-/** \example test_read_icon.c
+#include <mpi.h>
+
+/** \example test_read_icon_c.c
  * This contains examples for yac_read_icon_basic_grid_data.
  */
 
-#include <mpi.h>
+/** \example test_read_icon.F90
+ * This contains examples for yac_read_icon_basic_grid_data.
+ */
+
+/** \example test_read_icon_parallel_c.c
+ * This contains examples for parallel use of yac_read_icon_basic_grid_data.
+ */
 
-/** \example test_read_icon_parallel.c
+/** \example test_read_icon_parallel.F90
  * This contains examples for parallel use of yac_read_icon_basic_grid_data.
  */