Update CONTRIBUTING.md

Author: localden

CONTRIBUTING.md

@@ -21,7 +21,7 @@ These are one time installations required to be able to test your changes locall
 >[!IMPORTANT]
 >We leverage AI and AI agents for help with this project and value contributions that also use AI to detect issues and improve Spec Kit. However, to help the team focus on important issues and features, we will close issues and PRs that are **low-effort AI-generated changes**. If you are submitting an AI generated issue or pull request, please include **concrete test cases**, **scenarios**, and an outline of the **end-to-end developer experience** with your suggested change.
 >
->This means that you need to be supervising the changes and understanding why the change is necessary within the Spec Kit scope.
+>This means that you need to be supervising the changes and be able to explain why the change is necessary within the Spec Kit scope.
 
 1. Fork and clone the repository
 1. Configure and install the dependencies: `uv sync`