📝 Description

Implement a mask method that applies a custom mask pattern to a string, allowing flexible formatting of IDs, document numbers, credit cards, phone numbers, and other structured data. The method should accept a string and a custom pattern.

Closes #23

🎯 Type of Change

• 🐛 Bug fix
• ✨ New feature
• 🔧 Enhancement (improvement of existing feature)
• 📝 Chore (documentation, refactoring, etc)

✅ Implementation Checklist

Code

• Transformer created in src/Transformers/ implementing StringTransformerInterface
• PHPDoc @method added in src/StringMorpher.php
• PHPDoc @method added in src/Instances/StringMorpherInstance.php

Tests

• Tests created in tests/Transformers/
• Tests cover main use cases
• Tests cover edge cases (null, empty string, etc)
• All tests pass (vendor/bin/phpunit)

Quality

• Code passes linter (vendor/bin/phpcs)
• Code follows project standards

Documentation

• Method documented in docs/docs/methods/
• Usage examples included (static and fluent)
• Parameters and return values documented