Progress information

[Kikobeats]

First of all, thanks for this library, it looks amazing!

I discovered it because I'm async contributor and I needed a Promise based alternative.

The issue is related with p-progress, that reports you information about tasks progress.

For example: https://github.com/sindresorhus/p-progress/blob/master/example.js

Because you need to manually increment the progress counter, could be easy do this internally into aigle methods for increment the counter based in each step of the .parallel, .series, .each, .etc methods.

It could be expose as .onProgress method for get information about the job state.

The thing is, do you think make sense and could be useful expose this information?

[suguru03]

I really like the idea. However, I would like to deal with it very carefully.
Because it may affect performance and I don't think the feature isn't needed in general use cases.
But I like the idea, so I will look into it and think about a good solution for it. Thanks! 😄