chore(docs): Update README.md w/ usage comments

[cslee0034]

Address issue #2370: Fixed the comments in the usage section

const winston = require('winston');

const logger = winston.createLogger({
  level: 'info',
  format: winston.format.json(),
  defaultMeta: { service: 'user-service' },
  transports: [
    //
    // - Write all logs with importance level of `error` or higher to `error.log`
    //   (i.e., error, fatal, but not other levels)
    //
    new winston.transports.File({ filename: 'error.log', level: 'error' }),
    //
    // - Write all logs with importance level of `info` or higher to `combined.log`
    //   (i.e., fatal, error, warn, and info, but not trace)
    //
    new winston.transports.File({ filename: 'combined.log' }),
  ],
});

[DABH]

I think there's always some confusion around "higher" or "lower" when it comes to error level codes... but, the parentheticals here seem to disambiguate what the behavior is going to be, so overall, I am in favor of this PR. Thanks for your contribution.