Added a simple example

[davidedc]

Hi,

Just thought to add an example upscaler with the classic example image.

If you don't like the idea to add the example in the src, another option is to replace the current wiki example with this. The example in the wiki has two minor problems (ImageIO can't read from the filename as as string directly and there are one or two try/catched missing). Nothing major, but it just saves a couple of minutes to anyone wanting to do a quick try.

Hope it helps. Thanks a lot for the awesome work!

Cheers, Davide Della Casa