Markdown code blocks rendered using syntax highlighting

The markdown renderer from Qt Creator doesn't use syntax highlighting when rendering code blocks.

For example:

Below you have a C++ "Hello World" example:

```cpp
#include <iostream>

int main() {
  std::cout << "Hello World\n";
}
```

Notice that the editor has the proper syntax highlighting, while the rendering doesn't.

As a user I would prefer the rendering to be the same as the editor.