document image property access

[tomprogers]

Jimp can modify an image in a lot of ways, but the documentation doesn't explain how a person can access the image's current properties. Like reading its current width or height.

Expand the API documentation to cover all the members of the object returned by Jimp.read(...).

The only alternative is to traipse through all of the jimp source code. That should not be necessary.

Add any other context or screenshots about the feature request here.

[alfreema]

So, how DO you get an image's current width and height? :)

Edit: Code completion seems to indicate there are .getWidth() and .getHeight() functions.