feat(cli): enhance markdown generation with default content filters

Add DefaultMarkdownGenerator integration and automatic content filtering for markdown output formats. When using 'markdown-fit' or 'md-fit' output formats, automatically apply PruningContentFilter with default settings if no filter config is provided.

This change improves the user experience by providing sensible defaults for markdown generation while maintaining the ability to customize filtering behavior.

crawl4ai/__version__.py

@@ -1,2 +1,2 @@
 # crawl4ai/_version.py
-__version__ = "0.5.0.post4"
+__version__ = "0.5.0.post5"

crawl4ai/cli.py

@@ -2,6 +2,7 @@ import click
 import os
 import time
 
+from fastapi.datastructures import Default
 import humanize
 from typing import Dict, Any, Optional, List
 import json
@@ -24,6 +25,7 @@ from crawl4ai import (
     BM25ContentFilter, 
     PruningContentFilter,
     BrowserProfiler,
+    DefaultMarkdownGenerator,
     LLMConfig
 )
 from litellm import completion
@@ -614,17 +616,28 @@ def crawl_cmd(url: str, browser_config: str, crawler_config: str, filter_config:
             crawler_cfg = crawler_cfg.clone(**crawler)
             
         # Handle content filter config
-        if filter_config:
-            filter_conf = load_config_file(filter_config)
+        if filter_config or output in ["markdown-fit", "md-fit"]:
+            if filter_config:
+                filter_conf = load_config_file(filter_config)
+            elif not filter_config and output in ["markdown-fit", "md-fit"]:
+                filter_conf = {
+                    "type": "pruning",
+                    "query": "",
+                    "threshold": 0.48
+                }
             if filter_conf["type"] == "bm25":
-                crawler_cfg.content_filter = BM25ContentFilter(
-                    user_query=filter_conf.get("query"),
-                    bm25_threshold=filter_conf.get("threshold", 1.0)
+                crawler_cfg.markdown_generator = DefaultMarkdownGenerator(
+                    content_filter = BM25ContentFilter(
+                        user_query=filter_conf.get("query"),
+                        bm25_threshold=filter_conf.get("threshold", 1.0)
+                    )
                 )
             elif filter_conf["type"] == "pruning":
-                crawler_cfg.content_filter = PruningContentFilter(
-                    user_query=filter_conf.get("query"),
-                    threshold=filter_conf.get("threshold", 0.48)
+                crawler_cfg.markdown_generator = DefaultMarkdownGenerator(
+                    content_filter = PruningContentFilter(
+                        user_query=filter_conf.get("query"),
+                        threshold=filter_conf.get("threshold", 0.48)
+                    )
                 )
                 
         # Handle extraction strategy