Quick updates to the epub files

I don't actually have an ereader, so I was only recently made aware of the full possibilities of ~metadata~ they offer. So the epub files have a bit more of that now (title, author, language). Feel free to let me know if I've broken something in the course of replacing a bunch of files.

I've also taken the opportunity to replace the double short-dashes in stories 3-6 with proper long dashes. For some reason my LibreOffice has stopped auto-replacing those, which is very annoying.

Finally, I noticed and corrected an error in the Third Death of Trackboar--there are of course Nine Treasures of the Sideworlds, not Thirteen (that's the number of Treasures of the Isle of Britain in Welsh tradition; which isn't even what I swiped this idea from, it's supposed to be an analogue of the Irish Four Treasures of the Tuatha Dé Danann. There are some deliberate minor inconsistencies like this between different texts in the Gordian cycle beyond what our translator points out, but this one wasn't intentional and I don't think it added anything.