Type/Adi

bug: flet build windows gets stuck on packaging python app; and extension template generation issues

35

### Duplicate Check - [x] I have searched the [opened issues](https://github.com/flet-dev/flet/issues) and there are no duplicates ### Describe the bug I have been following the documentation on creating user extensions...

Added an example file for ReorderableListView, alongside an index.py.