Create comprehensive README.md documentation

[github-actions]

Create README.md Documentation

Description

Create a comprehensive README.md file for the Arithmetic Python library that provides clear documentation for users.

Acceptance Criteria

• Create README.md in the project root directory
• Include project title and brief description
• Document installation instructions
• Provide usage examples with code snippets
• Document the add function with examples
• Include information about supported Python versions
• Add development/contribution guidelines
• Include license information (if applicable)
• Use proper Markdown formatting

Dependencies

Depends on #3

Content Requirements

• Project overview explaining it's a library for basic arithmetic
• Installation section (pip install, local development setup)
• Usage section with add function examples
• API documentation section
• Examples showing different number types (int, float)
• Development section for contributors
• Clear, professional formatting