Fixes #248 (closed). Yeah, I know it's ugly, but even in this day and age Windows' splendid Notepad editor won't display a file with Unix line endings properly. It all becomes a single line which makes the About message somewhat hard to read. :)
Note that I'm definitely not suggesting that we have to change all the other text files in the docs. If a Windows user opens one of those, he's supposedly aware that he's opening a text editor and might be expected to run a real editor such as Emacs or Notepad++ as his default text editor.
But when a Windows user first runs Purr Data and clicks on the About Pd-l2ork menu command, we can't expect her to deal with this. It should display properly no matter what editor gets launched, and on Windows this will most likely be ye olde Notepad.
Since the change is harmless for Linux and Mac where editors actually know how to deal with DOS text files, I'd say that this is the easiest and most straightforward way to fix #248 (closed). Unless we want to add a "real" About box instead of just launching a text editor.