Update insitu.md

docs.it4i/software/viz/insitu.md

@@ -48,7 +48,7 @@ It will generate the CxxFullExampleAdaptor executable file. This can be later ru
 Provided example is a simple MPI program. Main executing part is written in FEDriver.cxx. It is a simulator code that creates computational grid   
 
 
-```javascript{.line-numbers}
+```c++
 #include ahoj.h
 
 int main() {