feat: add Contrabution guidelines

.github/CONTRIBUTING.md

@@ -0,0 +1,54 @@
+## Contribution Guidelines 🤝
+
+Thank you for considering contributing to the Design Patterns project! Your contributions play a vital role in improving the quality of this project. Follow these guidelines to contribute effectively:
+
+### Getting Started 🚀
+
+1. Fork the project by visiting [design-patterns](https://github.com/mutasim77/design-patterns) on GitHub and clicking the "Fork" button.
+2. Clone your forked repository to your local machine.
+
+```sh
+git clone https://github.com/your-username/design-patterns.git
+```
+
+Create a new branch for your contribution.
+
+```sh
+git checkout -b feature/your-feature
+```
+
+### Making Changes 🛠️
+1. Explore the project and choose the design pattern or SOLID principle you want to work on.
+2. Implement your changes or improvements to the selected design pattern or SOLID principle.
+3. In addition to code changes, I encourage contributors to provide a visual representation using [Excalidraw](https://excalidraw.com/). Follow these steps:
+   - Open the Excalidraw file in the .github directory.
+   - Make your changes in the Excalidraw file to visually represent the design pattern or SOLID principle you are working on.
+   - You can import the modified Excalidraw picture to the repository.
+
+### Committing Changes 📝
+
+1. Commit your changes with a descriptive commit message. 
+```sh
+git commit -m "feat: implement your-feature and add visual representation"
+```
+
+1. Push your changes to your forked repository.
+```sh
+git push origin feature/your-feature
+```
+
+### Creating a Pull Request (PR) 📥
+1. Go to the original repository on GitHub.
+2. Click on the "Pull Requests" tab.
+3. Click the "New Pull Request" button.
+4. Choose the branch with your changes.
+5. Describe your changes in the pull request and provide any necessary context.
+6. Submit the pull request.
+
+### Code Review ✅
+Once your pull request is submitted, it will undergo a review. Be open to feedback and address any comments or suggestions made by maintainers or contributors.
+
+### Contribution Acceptance 🎉
+After successful review, your contribution will be merged into the main repository. Congratulations, and thank you for your contribution to the Design Patterns project! ❤️‍🔥
+
+Happy coding! 🚀🎨