refactor(llm): rename LlmConfig to LLMConfig for consistency

Rename LlmConfig to LLMConfig across the codebase to follow consistent naming conventions.
Update all imports and usages to use the new name.
Update documentation and examples to reflect the change.

BREAKING CHANGE: LlmConfig has been renamed to LLMConfig. Users need to update their imports and usage.

crawl4ai/markdown_generation_strategy.py

@@ -1,9 +1,9 @@
 from abc import ABC, abstractmethod
-from tabnanny import verbose
 from typing import Optional, Dict, Any, Tuple
 from .models import MarkdownGenerationResult
 from .html2text import CustomHTML2Text
-from .content_filter_strategy import RelevantContentFilter
+from .types import RelevantContentFilter
+# from .content_filter_strategy import RelevantContentFilter
 import re
 from urllib.parse import urljoin