Update proxy configuration to use industry-standard environment variables
(HTTP_PROXY, HTTPS_PROXY, NO_PROXY) instead of custom variables.
The underlying libraries (esperanto, content-core, podcast-creator)
now automatically detect proxy settings from these standard variables.
- Bump content-core>=1.14.1 (fixes#494)
- Bump esperanto>=2.18
- Bump podcast-creator>=0.9
- Update documentation with new proxy configuration
- Replace old docs structure with new comprehensive documentation
- Organize into 8 major sections (0-START-HERE through 7-DEVELOPMENT)
- Convert CONFIGURATION.md, CONTRIBUTING.md, MAINTAINER_GUIDE.md to redirects
- Remove outdated MIGRATION.md and DESIGN_PRINCIPLES.md
- Fix all internal documentation links and cross-references
- Add progressive disclosure paths for different user types
- Include 44 focused guides covering all features
- Update README.md to remove v1.0 breaking changes notice
