更新 README

README.md

@@ -28,11 +28,11 @@
 ## Install
 To install lite version (`AcrylicLabel` is not available):
 ```shell
-pip install PyQt-Fluent-Widgets
+pip install PyQt-Fluent-Widgets -i https://pypi.org/simple/
 ```
 Or install full-featured version:
 ```shell
-pip install "PyQt-Fluent-Widgets[full]"
+pip install "PyQt-Fluent-Widgets[full]" -i https://pypi.org/simple/
 ```
 
 ## Run Example
@@ -42,6 +42,8 @@ cd examples/gallery
 python demo.py
 ```
 
+If you encounter `ImportError: cannot import name 'XXX' from 'qfluentwidgets'`, it indicates that the package version you installed is too low. You can replace the mirror source with https://pypi.org/simple and reinstall again.
+
 ## Documentation
 Want to know more about PyQt-Fluent-Widgets? Please read the [help document](https://pyqt-fluent-widgets.readthedocs.io/) 👈