[yakuwarigo-modifier] update zundamon rules

[umjammer]

yakuwarigo (役割語) modifier for ずんだもん is not completed.
it's just a copy of サロメ's rules and replaced "ですわ" into "なのだ" only.
so output text is not natural.

https://github.com/umjammer/vavi-speech/blob/master/src/main/resources/vavi/speech/modifier/yakuwarigo/zundamon.json