Generated PDF examples in README and tutorial

[epogrebnyak]

PDFje seems a great project in the making, congrats and good luck in making it happen. As a new user on the README for me it is interesting to see the ouput of PDFje. I think these files would be very pretty and attractive given the effort you invested in typography. A PDF link in readme can attract more people to the project.

Also adding inline markdown would be a killer feature. So far most workflows seem to be "md -> html -> pdf", but native and nice looking md-to-PDF is a game-changer.

Also as a new user, It wouldbe nice to have something in between a one-liner and a tutorial example (which is a bit too much code for a first-time user). Also downloading the resulting PDFs in tutorial is a matter of trust things work. Great if tutorial examples can be copy-and-run (I think they are not due to local paths, also constants-before-code makes the examples not so easy to read).

I know it is easier to point things inopen source, rather than do things, so I'd be interested in doing some work for the project - eg a bit of additions and clarifications to documentation.