Bump version to 0.1.4

Bump version to 0.1.3 and update Python compatibility

- Updated version in pyproject.toml and __init__.py to 0.1.3.
- Changed Python requirement to be less than 4.0.
- Enhanced SlackRenderer to handle rich text sections more effectively, including handling dividers and headers.
- Added additional rich_text_section elements in test data for better coverage.
- Cleaned up the collapse logic for rich text elements to avoid empty sections.

Update pypi package metadata

Initial commit