Add in a json logger as an extra

[maraisr]

I have found myself wanting to consume logs in a server runtime as json. This helps me consume/query/filter logs in a far easier manner, than parsing the messages.

To do this, and w/o forcing this on users I will expose a new entrypoint diary/middleware .

The idea being, that here we'll the suite of hooks?? (might not) as well as a collection of "baked-in" plugins, like json and maybe request logger. etc.

Maybe api:

import { json } from 'diary/middleware';
import { diary } from 'diary';

const logger = diary('');

json(); // will assume global
json(logger); // will just log as json for `logger`