Add contributing guidelines to the Python Environments extension (#1012)

Author: eleanorjboyd

CONTRIBUTING.md

@@ -0,0 +1,75 @@
+# Contributing to Python Environments Extension
+
+Thank you for your interest in contributing to the Python Environments extension! This guide will help you get started.
+
+## Prerequisites
+
+- Node.js (LTS version recommended)
+- npm
+- VS Code Insiders (recommended for development)
+- Git
+- Python
+
+## Getting Started
+
+1. **Clone the repository**
+   ```bash
+   cd vscode-python-environments
+   ```
+
+2. **Create a Python virtual environment** 
+
+3. **Install dependencies**
+   ```bash
+   npm install
+   ```
+
+4. **Build and watch**
+   ```bash
+   npm run watch
+   ```
+
+5. **Run tests**
+   ```bash
+   npm run unittest
+   ```
+
+## Development Workflow
+
+### Running the Extension
+
+1. Open the project in VS Code
+2. Press `F5` to launch the Extension Development Host
+3. The extension will be loaded in the new VS Code window
+
+### Making Changes
+
+- **Localization**: Use VS Code's `l10n` API for all user-facing messages
+- **Logging**: Use `traceLog` or `traceVerbose` instead of `console.log`
+- **Error Handling**: Track error state to avoid duplicate notifications
+- **Documentation**: Add clear docstrings to public functions
+
+### Testing
+Run unit tests with the different configurations in the "Run and Debug" panel
+
+## Contributor License Agreement (CLA)
+
+This project requires contributors to sign a Contributor License Agreement (CLA). When you submit a pull request, a CLA bot will automatically check if you need to provide a CLA and guide you through the process. You only need to do this once across all Microsoft repositories.
+
+## Code of Conduct
+
+This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information, see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with questions.
+
+## Questions or Issues?
+
+- **Questions**: Start a [discussion](https://github.com/microsoft/vscode-python/discussions/categories/q-a)
+- **Bugs**: File an [issue](https://github.com/microsoft/vscode-python-environments/issues)
+- **Feature Requests**: Start a [discussion](https://github.com/microsoft/vscode-python/discussions/categories/ideas)
+
+## Additional Resources
+
+- [Development Process](https://github.com/Microsoft/vscode-python/blob/main/CONTRIBUTING.md#development-process)
+- [API Documentation](./src/api.ts)
+- [Project Documentation](./docs/projects-api-reference.md)
+
+Thank you for contributing! 🎉