Implement master branch creation from main branch

[Copilot]

This PR implements the requested git workflow to create a master branch from the main branch. The implementation provides a robust shell script that executes the exact commands specified in the problem statement:

1. git checkout main
2. git checkout -b master
3. git push origin master

What's Added

New Script: create-master-branch.sh

• Automates the master branch creation process
• Includes comprehensive error handling and validation
• Provides clear visual feedback with colored output
• Handles edge cases like existing branches gracefully

Key Features

• Error Handling: Validates git repository existence and branch availability
• Idempotent: Can be run multiple times safely - switches to existing master branch if it already exists
• Visual Feedback: Uses colored terminal output to indicate progress and status
• Documentation: Includes clear comments explaining the purpose and implementation

Usage

./create-master-branch.sh

The script will:

• Verify you're in a git repository
• Switch to the main branch
• Create a new master branch (or switch to existing one)
• Push the master branch to origin

This implementation ensures that repositories can maintain both main and master branches as needed, which may be required for legacy compatibility or organizational standards.

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