add basic PureScript coverage

Building with the Nix derivation, this appeared to work for me in a variety of samples.

However, there's not a reasonable way to cover a large part of language around casing. In PureScript, an identifier must be a lowercase character in any bicameral script followed by a character, but neither :lower: nor \l work and neither does \w work as I would expect in this context. In PureScript, there would be nothing wrong with naming a function նຮᮠa with a lower from Armenian, then Lao, then Sundanese, then Latin. The Unicode ranges, could be done, but man that would be a mess (where Greek for instance interlaces lower and upper).

As such, I've just covered Greek and Cyrillic, but I spent enough time trying to cover these. This should be something available through the Regex engine.