stringify adds underscore as integer decimal separator

[zanona]

Hello :wave:, I am a bit intrigued with the fact that integers are added an underscore as a decimal separatorssuch as:

const a = {number:10000};
toml.stringify(a) // number=10_000

repro: https://codesandbox.io/s/iarnatoml-stringify-45080?file=/src/index.js

This is being used for both integers and floats https://github.com/iarna/iarna-toml/blob/1374bf2f151aa23e32fecadceb49d4411c9b7adf/stringify.js#L188-L191

But it would great allowing users to disable it in case they prefer it without separators in order to improve editability?