Add documentation for the language plugin that provides URL-based
internationalization support with language-specific URLs, content files,
slugs, and translations
Refactor to use plugin system for language support
Remove hardcoded language features from core
Move language handling to plugin system
Improve content file discovery
Simplify context creation
Add plugin system documentation
Implement hook system for extensibility
Add template variable hook
Add context storage for plugins
Improve error handling
Refactor rendering logic
Improve list view sorting
Add support for custom list templates
Improve metadata handling
Add plugin system reference documentation