Add ruff badge (#72)

README.md

@@ -3,8 +3,7 @@
 [![Twitter](https://badgen.net/badge/icon/twitter?icon=twitter&label)](https://twitter.com/vladkurenkov/status/1669361090550177793)
 [![arXiv](https://img.shields.io/badge/arXiv-2210.07105-b31b1b.svg)](https://arxiv.org/abs/2210.07105)
 [<img src="https://img.shields.io/badge/license-Apache_2.0-blue">](https://github.com/tinkoff-ai/CORL/blob/main/LICENSE)
-[![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
-[![Imports: isort](https://img.shields.io/badge/%20imports-isort-%231674b1?style=flat&labelColor=ef8336)](https://pycqa.github.io/isort/)
+[![Ruff](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/charliermarsh/ruff/main/assets/badge/v2.json)](https://github.com/astral-sh/ruff)
 
 
 🧵 CORL is an Offline Reinforcement Learning library that provides high-quality and easy-to-follow single-file implementations of SOTA ORL algorithms. Each implementation is backed by a research-friendly codebase, allowing you to run or tune thousands of experiments. Heavily inspired by [cleanrl](https://github.com/vwxyzjn/cleanrl) for online RL, check them out too!<br/>