Update README.md to clarify specifying orientation from Exif data

[Nateowami]

Clarified how to use the orientation option, and changed wording regarding the Exif parser.

Regarding the orientation option, from the original wording I thought the meaning was that you could simply enable the orientation option (e.g. by setting it to true), but from reading the source code for the demo, I see you have to determine the orientation separately with the loadImage.parseMetaData function.

On a side note, it might be worth making it an option to correct the orientation in a single function call. Fixing the orientation is the single reason I'm using this library (HTMLImageElement provides decent functionality out of the box), and I'm guessing the same could be for many others users of this library.

Thoughts on my proposed wording changes? I'm not completely happy with the wording I cam up with, but it seems clearer to me than the original wording.

[blueimp]

Thanks @Nateowami, I've also just added the new options meta:true and orientation:true:
https://github.com/blueimp/JavaScript-Load-Image#options

[Nateowami]

Thanks, that's great!