fix #1489

Former-commit-id: ebdeaca9cdfd6138c690a0fcb9f676deaddff177

src/cli_demo.py

@@ -1,6 +1,12 @@
-import readline
 from llmtuner import ChatModel
 
+try:
+    import platform
+    if platform.system() != "Windows":
+        import readline
+except ImportError:
+    print("Install `readline` for a better experience.")
+
 
 def main():
     chat_model = ChatModel()