docs: def settings(instance):
      """Definition to set settings from config file to the app instance."""
      with open(instance.root_dir + '/Config/config.yml') as config:
          config = yaml.load(config)
          instance.name = config['name']
          instance.port = config['web']['port']
          # default host
          instance.host = "http://localhost"
          if 'host' in config['web']:
              instance.host = config['web']['host']
          instance.debug = config['debug']
      return instance