Usage of batch processing in README.md is misleading

[michael-o]

The README says:

batch conversion of multiple files: pngquant *.png

Let's try:

$ /tmp/pngquant/bin/pngquant --skip-if-larger --verbose --ext .png -f 'inputs/Bilder.toy/*'
inputs/Bilder.toy/*:
  error: cannot open inputs/Bilder.toy/* for reading
There were errors quantizing 1 file out of a total of 1 file.

Does not work.
Reason: The README relies on the fact that the tool is run from a shell which supports file globbing, but the tool itself does not use glob(3). Better replace with multiple filenames. As soon as I run this example from a non-shell, e.g., Java, Python, popen it will fail.