Add doc page or blog post on Java usage

[ingydotnet]

From #269:

Yes, 0.2.23 worked for me, although I am missing any docs on how to make the library work for me. I guessed around a bit, and got a sample file from the YAMLStar repository and some clues. It really begs for a more Java oriented wrapper around it all, as casting is kinda not idiomatic Java. I've included the code that eventually worked, should it be helpful for anyone else who should also be new to this and need some direction.