Add information to docs on how to add additional fields in error

[vladshcherbin]

Jesus, I've spent so much time to find how to do it.

http-errors has possibility to add additional fields to error like this:

createError(503, 'No work on the sabbath.', { type: 'DayError' , expose: true })

However, formatError function cuts all additional properties and produces only message field. To add this additional error fields you have to use extensions property like this:

createError(503, 'No work on the sabbath.', { extensions: { type: 'DayError' }, expose: true })

This will correctly show additional error information to user:

Please, add this to docs somewhere. I really hope it will help and save time for someone else.

❤️

[jaydenseric]

Just published graphql-api-koa@4.1.2, this stuff should be easier now 🙏

[vladshcherbin]

@jaydenseric thank you a lot, using it in my current project ❤️