Caveats about cyrilic: overlapping characters between languages like Bulgarian or Serbian

[melounek]

Could we add an option lang which would resolve many of caveats mentioned in the docs?

As a first simple use-case it could handle languages sr, bg and maybe few more cyrilic ones so that the transliteration can me made without mistakes. Here is solution in python which I didn't find for NodeJS anywhere else and this library looks like a good fit to handle this cyrilic-to-latin feature.

Let me know what you think and if I should try to do a PR for that.