Breaking: take in custom formatter option

[JaneJeon]

See https://github.com/pinojs/pino/issues/1376

Changes:

• instead of a default format function, export a builder for the format function instead (this is the breaking bit, and is needed to make this library configurable; I was not able to get it to work using the trick mentioned in the other thread)
• take in a custom formatters opt and run interpolation with it (the actual feature bit)
• using predefined consts instead of using magic numbers (please feel free to revert this should you feel the need to)
• tons of code formatting, I'm really sorry about this, I was too weak to stop vscode/prettier

[JaneJeon]

@davidmarkclements bump? https://github.com/pinojs/pino/issues/1376

[mcollina]

You can make this non-breaking by doing:

function build(opts) { ... }
const formatter = build(theDefaultOpts)
module.exports = formatter
module.exports.build = build

[davidmarkclements]

hey thanks for this

• let’s not break the API if we don’t need to, @mcollina suggestions seems good to me
• 👍
• 👍
• If any code formatting is applied it will need to be standard linting or else originally formatted before we can merge