Create CONTRIBUTING.md with contribution guidelines

Added a comprehensive contributing guide for the project, detailing setup, code guidelines, and contribution expectations.

Author: F-3-R-R-3

CONTRIBUTING.md

@@ -0,0 +1,91 @@
+# Contributing to ReShaped
+
+Thank you for considering contributing to ReShaped. Contributions are welcome and appreciated.
+
+## Getting Started
+
+1. Fork this repository on GitHub
+2. Clone your fork:
+```bash
+   git clone https://github.com/F-3-R-R-3/reshaped-1.20.1.git
+```
+4. Enter the project folder:
+```
+   cd reshaped-1.20.1
+```
+6. Create a new branch:
+```
+   git checkout -b feature/your-change
+```
+> [!TIP]
+> Or alternatively, you can use the bultin Git functionallity of IDE's like Intellij (<- reccomended) or VSCode to clone this repo locally and create a branch.
+> You can always ask me for help setting up a coding environment and git branch by creating a Github issue!
+
+## Development Setup
+
+This project is a Fabric mod for Minecraft 1.20.1.
+
+Requirements:
+- Java 17 or higher
+- Gradle (wrapper included)
+
+Run the client in development mode:
+./gradlew runClient
+
+Build the mod:
+./gradlew build
+
+The output jar will be located in:
+build/libs
+
+## Code Guidelines
+
+- Keep code clean and readable
+- Follow existing project structure
+- Use clear naming for classes and methods
+- Avoid large unrelated changes in one pull request
+
+## What You Can Contribute
+
+- Bug fixes
+- Performance improvements
+- New block or shape logic
+- Compatibility fixes with other mods
+- UI or usability improvements
+- Refactoring and cleanup
+
+## Issues
+
+Before opening an issue:
+- Check if it already exists
+- Include Minecraft version and mod version
+- Add logs or screenshots if possible
+- Provide steps to reproduce the problem
+
+## Pull Requests
+
+When submitting a pull request:
+- Clearly describe what changed
+- Keep changes focused
+- Ensure the mod still runs and builds
+- Test in-game before submitting
+
+## Important Systems
+
+Be careful when modifying:
+- Block associations
+- Block registration
+
+These parts affect global mod behavior.
+
+## AI Usage
+
+AI-generated code is allowed.
+
+Please review, test, and understand any AI-generated code before submitting it. Contributions are judged by their quality and maintainability, not by whether AI was used.
+
+I use AI tools myself, but I try to keep their use to a minimum whenever possible.
+
+## License
+
+By contributing, you agree that your code will be licensed under the same license as the project (LGPL-3.0).