Add contributing notes

CONTRIBUTING.md

@@ -0,0 +1,47 @@
+# Contributing to Penpot MCP
+
+Thank you for your interest in contributing to Penpot MCP!
+
+## Scope of Contributions
+
+Small bug fixes, documentation improvements, and minor enhancements can be submitted
+directly via pull requests.
+
+For significant changes or non-trivial new features, please open an issue first to discuss 
+your ideas with the maintainers.
+
+## Code Style
+
+This project uses [Prettier](https://prettier.io/) for code formatting.
+
+Please strive for local consistency with the existing code style when making changes.
+
+### Formatting Your Code
+
+Before committing changes, please format your code by running:
+
+```bash
+npm run format
+```
+
+Please refrain from using additional auto-formatting tools to avoid
+unnecessary diffs.
+
+To check if your code is properly formatted without modifying files:
+
+```bash
+npm run format:check
+```
+
+## Submitting Changes
+
+1. Fork the repository
+2. Create a new branch for your changes
+3. Make your changes following the code style guidelines
+4. Run `npm run format` to format your code
+6. Submit a pull request with a clear description of your changes
+7. Ensure all CI checks pass
+
+## Questions?
+
+If you have questions or need help, please use [GitHub discussions]().