external knowledge api (#8913)

Co-authored-by: Yi <yxiaoisme@gmail.com>

api/core/rag/entities/context_entities.py

@@ -0,0 +1,10 @@
+from pydantic import BaseModel
+
+
+class DocumentContext(BaseModel):
+    """
+    Model class for document context.
+    """
+
+    content: str
+    score: float