feat: add Portuguese (pt-BR) translation support

[CodeByDeepankar]

🌐 Add Portuguese (pt-BR) Internationalization Support

📋 Summary

This PR adds complete Portuguese (Brazil) translation support to the GitHub Profile README Generator, making the application fully bilingual (English/Portuguese).

✨ Features Added

🔧 i18n Infrastructure

• Added react-i18next and i18next for internationalization
• Implemented language detection and localStorage persistence
• Created translation file structure under src/i18n/locales/

🌐 Complete Portuguese Translation

• UI Components: Header, Footer, Navigation, Buttons
• Form Fields: All input placeholders and labels
• Work Section: All 10 work-related input fields and prefixes
• Social Platforms: 25+ social media platform placeholders
• Skills Section: Search functionality and skill labels
• Addons: GitHub stats, streak stats, Twitter badge, dynamic blogs
• Validation: All error and warning messages
• Dynamic Defaults: Smart translation of default values

🎨 UI Improvements

• Language Selector: Modern dropdown menu replacing button layout
• Real-time Switching: Instant language changes without page reload
• Visual Feedback: Clear indication of selected language
• Responsive Design: Maintains existing design consistency

🛠️ Technical Implementation

Files Added:

• src/i18n/index.js - i18n configuration
• src/i18n/locales/en.json - English translations (154 keys)
• src/i18n/locales/pt-BR.json - Portuguese translations (154 keys)
• src/components/languageSelector.jsx - Language switcher component

Files Modified:

• src/components/layout.jsx - Added i18n initialization and language selector
• src/components/header.jsx - Translated nav elements
• src/components/footer.jsx - Translated footer content
• src/components/work.jsx - Added translation hooks for all form fields
• src/components/social.jsx - Translated all social platform placeholders
• src/components/addons.jsx - Translated addon features and descriptions
• src/components/title.jsx - Added title translation support
• src/components/subtitle.jsx - Added subtitle translation with placeholder
• src/pages/index.jsx - Added dynamic default translation system and validation messages

Dependencies Added:

"react-i18next": "^11.18.6",
"i18next": "^21.10.0",
"i18next-browser-languagedetector": "^6.1.8"

[CodeByDeepankar]