Allow cyrillic letters in book names

[anareaty]

Right now if the book name is in cyrillic alphabet, book folder is created with an empty name. It can be easily fixed, you just need replace this line:

const sanitized_book_title = book.title.replace(/[^a-zA-Z0-9 -]/g, "");

with this:

const sanitized_book_title = book.title.replace(/[^a-zA-Zа-яА-ЯёЁ0-9 -]/g, "");

It would probably be useful to add some other alphabets symbols too.

[lenalebt]

Probably the same as in #3 . I'll have a look :-)

[lenalebt]

Should be working in 0.1.6 now, I switched from an allowlist of characters to a blocklist, which should address my fear of using disallowed characters for some file systems :-). Feel free to reopen if the issue persists somehow.