func/logger library

1. dio_cache_ttl package
2. documentation
3. func/logger.dart

dio_cache_ttl package

1. Libraries
2. dio_cache_ttl
3. func/better_name
4. func/check_cache
5. func/clear_cache
6. func/dio_cache
7. func/download_file
8. func/get_dir
9. func/logger