release 0.2.0 - define all transitive dependencies and pin within semvar major.minor range

[anthonywu]

Pin All Dependencies Within Semver Minor Range

This PR comprehensively defines the project's dependency management to pin all dependencies within semver major.minor ranges, improving flexibility when chatterbox-tts is used as a dependency from an app-layer such as my own https://github.com/anthonywu/gensay

• Bumped this library's version from 0.1.2 to 0.2.0 to reflect dependency management changes
• Pinned all 50+ dependencies to specific minor versions as discovered on 2025-07-31 (e.g., >=1.0,<2.0 format)
• Dependency versions are compatible with status quo Python 3.9, verified via uv tool install -p 3.9 chatterbox-tts which is an isolated install check/solve
• Sorted dependencies alphabetically for better maintainability
• Added optional demo dependency group for Gradio
• Updated core dependencies: numpy (1.26.0 → >=2,<3.0), torch (2.6.0 → >=2.7,<3.0), transformers (4.46.3 → >=4.54,<5.0)
• Added missing transitive dependencies explicitly to ensure consistent environments
• All dependencies now follow consistent semver minor range pinning pattern

This change ensures this library can be depended on by another application without unreasonably constraining to a set of lib versions ==ed during a very specific point in time, which would cause increasing number of pip install resolution errors as time passes.