Add jieba for Chinese TTS models (#797)

sherpa-onnx/csrc/offline-tts-vits-model-metadata.h

@@ -22,6 +22,10 @@ struct OfflineTtsVitsModelMetaData {
   bool is_coqui = false;
   bool is_icefall = false;
 
+  // for Chinese TTS models from
+  // https://github.com/Plachtaa/VITS-fast-fine-tuning
+  int32_t jieba = 0;
+
   // the following options are for models from coqui-ai/TTS
   int32_t blank_id = 0;
   int32_t bos_id = 0;