message: config: when file doesn't exist, create it with default settings.
diff: @@ -77,10 +77,9 @@ void createFileIfNotExists(FileSystem::path const& _path)
  auto const& status = FileSystem::status(_path, errorCode);
  if (!FileSystem::is_regular_file(status))
  {
  - ofstream file(_path.string(), ios_base::out);
  - if (!file.good())
  - throw runtime_error{ string("Unable to create config file. ") + (errorCode ? errorCode.message() : "") };
  - file.close();
  + Config freshConfig{};
  + freshConfig.inputMappings = Config::defaultInputMappings();
  + saveConfigToFile(freshConfig, _path.string());
  }
  }
  @@ -416,6 +415,12 @@ std::string serializeYaml(Config const& _config)
  void saveConfigToFile(Config const& _config, std::string const& _fileName)
  {
  + FileSystemError errorCode;
  + auto const& status = FileSystem::status(_fileName, errorCode);
  +
  auto ofs = ofstream{_fileName, ios::trunc};
  + if (!ofs.good())
  + throw runtime_error{ string("Unable to create config file. ") + (errorCode ? errorCode.message() : "") };
  +
  ofs << serializeYaml(_config);
  }
  