v2

What's Changed

• Add various features and architecture in #6
• Update README with features, user guide, and new images in #7

1. Key features implemented:

• Save and edit AWS credentials
• Region selection with dropdown (replaced manual entry)
• Engine selection based on region selected
• Language selection
• Voice selection with gender information
• Output format selection (mp3, ogg_vorbis, pcm)
• Sample rate selection based on output formats
• Generate audio and play immediately

2. UI enhancement:

• Dedicated credentials editing screen
• Main navigation page to different TTS service
• Status bar message for loading and error messages
• Real-time character counter

3. Architecture and quality

• Main controller (TTSAppController) for app flow
• MVC pattern implementation
• Enhanced error handling
• Credential verification before save