fix: contributing guide

Author: shawnhankim

CONTRIBUTING.md

@@ -32,12 +32,10 @@ To suggest a feature or enhancement, please create an issue on GitHub with the l
 
 - Fork the repo, create a branch, implement your changes, add any relevant tests, submit a PR when your changes are **tested** and ready for review.
 
-  - Unit test: run `make test` for NGINX OSS and `make test-plus` for NGINX Plus
-  - Integration/Manual test: ensure that your changes work in either your app or the following runtime
+  - **Unit Test**: run `make test` for NGINX OSS and `make test-plus` for NGINX Plus
+  - **Integration/Manual test**: ensure that your changes work in either your app or the following runtime
     - [`nginx-s3-gateway`](https://github.com/nginxinc/nginx-s3-gateway)
     - [`nginx-lambda-gateway`](https://github.com/nginx-serverless/nginx-lambda-gateway)
-
-  Make sure that you also manually test this library that is integrated with the runtime such as `nginx-s3-gateway` and `nginx-lambda-gateway`.
 
 - Fill in [our pull request template](https://github.com/nginxinc/nginx-aws-signature/blob/main/.github/pull_request_template.md).