Add %O formatter

[thom4parisot]

As of https://developer.chrome.com/devtools/docs/console-api#consolelogobject-object

%O Formats the value as an expandable JavaScript object.

Unless if it not a "standard"? I guess the formatting should be the same as if the object was passed as the first argument of debug.

const payload = { hello: 'world' };

debug('%O', payload);
// ===
debug(payload)

Any opinion on this?

[thom4parisot]

Hm, it appears that actually this is the same as the %o formatter. Maybe just aliasing it to match other console implementations?

[TooTallNate]

For Node.js you mean? Ya sure, patch welcome.