adds contributing.md file

Author: Mohammod Al Amin Ashik

CONTRIBUTING.md

@@ -0,0 +1,49 @@
+# Contributing to Sitecore Marketplace SDK
+
+Thank you for your interest in contributing! We welcome contributions from the community to help improve this project.
+
+## How to Contribute
+
+1. **Fork the repository** and create your branch from `main`.
+2. **Install dependencies** using `pnpm install`.
+3. **Make your changes** in a new branch.
+4. **Write and run tests** to ensure your changes are correct.
+5. **Submit a pull request** with a clear description of your changes.
+
+## Code Style
+
+- Follow the existing code style and conventions.
+- Use TypeScript for all new code.
+
+## Commit Messages
+
+- Use clear, descriptive commit messages.
+- Reference related issues when applicable.
+
+## Changesets
+
+- All pull requests must include a [changeset](https://github.com/changesets/changesets) describing the changes.
+- To add a changeset, run:
+  ```sh
+  pnpm changeset
+  ```
+- If your PR does not affect published packages (e.g., docs-only or CI changes), add an empty changeset by running:
+  ```sh
+  pnpm empty-changeset
+  ```
+
+## Reporting Issues
+
+- Use the issue tracker to report bugs or request features.
+- Provide as much detail as possible.
+
+## Code of Conduct
+
+- Be respectful and inclusive.
+- Follow the [Sitecore Code of Conduct](https://github.com/Sitecore/.github/blob/main/CODE_OF_CONDUCT.md).
+
+## Questions?
+
+If you have any questions, open an issue or start a discussion.
+
+Thank you for helping make this project better!