docs: Add CONTRIBUTING.md with development setup guide

- Add comprehensive contributing guide with pre-commit setup instructions
- Include code quality standards and testing requirements
- Document commit process and CI/CD pipeline

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: codebydivine

CONTRIBUTING.md

@@ -0,0 +1,95 @@
+# Contributing to divine-thegraph-token-api
+
+## Development Setup
+
+### 1. Clone the repository
+```bash
+git clone https://github.com/codebydivine/token-api.git
+cd token-api
+```
+
+### 2. Create a virtual environment
+```bash
+python3 -m venv .venv
+source .venv/bin/activate  # On Windows: .venv\Scripts\activate
+```
+
+### 3. Install development dependencies
+```bash
+pip install -e ".[dev]"
+```
+
+### 4. Set up pre-commit hooks
+```bash
+# Run the setup script
+./scripts/setup-hooks.sh
+
+# Or manually:
+pre-commit install
+```
+
+## Code Style
+
+This project uses automated code formatting and linting:
+
+- **ruff**: For code formatting and linting
+- **mypy**: For type checking
+- **pre-commit**: Automatically runs formatters before each commit
+
+### Manual formatting
+```bash
+# Format all files
+pre-commit run --all-files
+
+# Or just ruff
+ruff format .
+ruff check --fix .
+```
+
+### Commit hooks
+When you commit, pre-commit will automatically:
+1. Format your code with `ruff format`
+2. Fix linting issues with `ruff check --fix`
+3. Remove trailing whitespace
+4. Ensure files end with a newline
+5. Check YAML/JSON/TOML syntax
+6. Run mypy type checking
+
+If any files are modified by the hooks, the commit will fail and you'll need to:
+1. Review the changes
+2. Stage them with `git add`
+3. Commit again
+
+### Bypassing hooks (not recommended)
+```bash
+git commit --no-verify
+```
+
+## Running Tests
+
+```bash
+# Run all tests with coverage
+pytest
+
+# Run specific test file
+pytest tests/test_evm_api.py
+
+# Run with verbose output
+pytest -v
+```
+
+## Making Changes
+
+1. Create a new branch: `git checkout -b feature/your-feature`
+2. Make your changes
+3. Ensure tests pass: `pytest`
+4. Commit your changes (pre-commit will format automatically)
+5. Push and create a pull request
+
+## Code Quality Standards
+
+- Maintain >90% test coverage
+- All functions should have type hints
+- Follow the existing code style
+- Add tests for new functionality
+- Update documentation as needed