OptionalcapitalizeWhether to capitalize the first letter of each word.
OptionalpolyphoneMode for handling polyphones (characters with multiple pronunciations).
OptionalpreserveWhether to preserve non-Chinese characters in the output.
OptionalseparatorSeparator between syllables.
OptionaltoneFormat for tone markers.
OptionalurlWhether to produce URL-safe output (ASCII only, no tones, no special chars).
When true, forces toneFormat to 'none', removes apostrophes, and converts ü to u.
This applies to both the joined text and each segments[].wadeGiles.
Options for configuring Wade-Giles conversion.