Add documentation example of different transports for different levels

[domenic]

The "Motiviation" section of the readme says

Each instance of a winston logger can have multiple transports configured at different levels. For example, one may want error logs to be stored in a persistent remote location (like a database), but all logs output to the console or a local file.

I've been through the readme three or four times, but still can't see how to accomplish this. Could an example of such be added to the docs?

For example, I want to send info (and above) to a file, but error (and above) to email me. How do I create a logger that does this?

[domenic]

Argggggh of course I see it thirty seconds after logging the issue. It's not mentioned in the "Using Log Levels" section, but instead mentioned in each of the individual transport documentation sections:

The Console transport takes two simple options:

level: Level of messages that this transport should log (default 'debug').

I'll do a pull request to add a note to the "Using Log Levels" section.

[coderarity]

Also note that this option is actually part of the base Transport, so all of the transports will support it just by inheriting from Transport.

[coderarity]

Fixed in 16dc3a9.