message: Add comment simple-solver example
diff: @@ -67,6 +67,7 @@ int main(int argc, char* argv[])
  // Print the ginkgo version information.
  std::cout << gko::version_info::get() << std::endl;
  + // Print help on how to execute this example.
  if (argc == 2 && (std::string(argv[1]) == "--help")) {
  std::cerr << "Usage: " << argv[0] << " [executor] " << std::endl;
  std::exit(-1);
  