docs: add section on how to use the dev logger

```js
import { Magnetar } from '@magnetarjs/core'
import { logger } from '@magnetarjs/utils'

export const magnetar = Magnetar({
localStoreName: 'local',
stores: { local, remote },
executionOrder: {
read: ['local', 'remote'],
write: ['local', 'remote'],
delete: ['remote', 'local'],
},
on: process.env.DEV ? { success: logger } : {},
})

```

> Main Setup/Example: `on: { success: logger }, // disable this on production builds`. I think you need to add an example or some help on how to do this. (A check on process.env for example)