helpers/add_frame library

1. pagify package
2. documentation
3. helpers/add_frame.dart

pagify package

1. Libraries
2. extensions/null_extension
3. extensions/zero_extension
4. generated/assets
5. helpers/add_frame
6. helpers/custom_bool
7. helpers/data_and_pagination_data
8. helpers/errors
9. helpers/status_stream
10. pagify
11. widgets/pagination_helper_refresh_indicator