Add instruction to set up pre-commit hooks. (#1029)

Signed-off-by: Xiongfei Wei <[email protected]>

Author: vanbasten23

CONTRIBUTING.md

@@ -31,5 +31,17 @@ We choose to follow a similar directory structure as vLLM:
 ## Testing
 When checking in a new feature, we expect that you you add relevant unit tests as well as CI tests.  You can read more about the latter [here](https://github.com/vllm-project/tpu-inference/tree/main/.buildkite#adding-a-new-feature-to-ci).
 
+## Setting up linting, formatting, and static type checking
+
+```
+pip install pre-commit
+
+# Linting, formatting and static type checking
+pre-commit install --hook-type pre-commit --hook-type commit-msg
+
+# You can manually run pre-commit with
+pre-commit run --all-files
+```
+
 ## Thank You!
 We wanted to thank you for taking the time to read these guidelines and for your interest in contributing to TPU Inference. All of your contributions help make TPU Infernece a great tool and community for everyone!