docs: add comment for model_path process

Author: WenqiOfficial

astrbot/core/provider/sources/nvidia_rerank_source.py

@@ -59,6 +59,7 @@ def _get_endpoint(self) -> str:
         model_path = "nvidia"
         logger.debug(f"[NVIDIA Rerank] Building endpoint for model: {self.model}")
         if "/" in self.model:
+            """遵循NVIDIA API的URL规则，替换模型名中特殊字符"""
             model_path = self.model.strip("/").replace(".", "_")
         endpoint = self.model_endpoint.lstrip("/")
         return f"{self.base_url}/{model_path}/{endpoint}"