Override AppSignal group in Winston child logger attributes

[unflxw]

Say, you have a Winston logger that uses our transport:

const { WinstonTransport } = require("@appsignal/nodejs");
const logger = winston.createLogger({
  transports: [
    new WinstonTransport({group: "app"})
  ]
);

And you create child loggers for different parts of your application:

const adminLogger = logger.child({group: "admin"})

Our transport could pick up this "group" attribute and use it to override the group that was set when the transport was created. That way, you can segment your applications' logs by group using Winston child loggers.

This was suggested in #826.

TO-DO

• Use "group" attribute as logger group if present - #865
• Update documentation - https://github.com/appsignal/appsignal-docs/pull/1107