feat(cli): add command line interface with comprehensive features

Implements a full-featured CLI for Crawl4AI with the following capabilities:
- Basic and advanced web crawling
- Configuration management via YAML/JSON files
- Multiple extraction strategies (CSS, XPath, LLM)
- Content filtering and optimization
- Interactive Q&A capabilities
- Various output formats
- Comprehensive documentation and examples

Also includes:
- Home directory setup for configuration and cache
- Environment variable support for API tokens
- Test suite for CLI functionality

docs/examples/cli/extract_css.yml

@@ -0,0 +1,3 @@
+type: "json-css"
+params:
+  verbose: true