v0.18.0

• Updated type for EmptyNull and EmptyOption literals (option<S.unknown> -> unit)
• Added NaN literal
• Removed S.literalUnit. For EmptyNull, EmptyOption and NaN use S.literal instead, and for other literals use S.literalVariant(literal, ())
• Float struct factory started returning error trying to parse NaN
• Added built-in refinements and transforms. You can check all of them out in documentation: