Support for lz4 compression #163

- [X] changes on `__init__.py` - [x] update `README.md` - [x] update tests - [x] update `ci.yml` - [X] add `lz4` to dependencies - [x] benchmark with and without `io.BufferedWriter` -> **remove** `io.BufferedWriter` for lz4 - [x] benchmark python lz4 vs lz4 CLI - [x] set lz4 compression levels aligned with python lz4 [0-16], as CLi accepts those values without problem.