logger/outputs/combined_observer library

1. tool_logger package
2. documentation
3. logger/outputs/combined_observer.dart

tool_logger package

1. Libraries
2. logger
3. logger/formatter/simple_message_logger_formatter
4. logger/logger
5. logger/non_fatal_exception
6. logger/outputs/combined_observer
7. logger/outputs/console_chunk_output
8. logger/outputs/file_with_logs_output
9. logger/talker_logger