Increase timeout by 10 seconds for checking links (#52)

This has been reported as an issue multiple times where we flag alive urls as dead due to delayed response from the server.

Author: john0isaac

src/markdown_checker/links/link_operations.py

@@ -102,7 +102,7 @@ def check_url_alive(urls: List[str]) -> List[str]:
         if "https://vscode.dev/redirect?url=" in url:
             continue
         try:
-            response = requests.get(url, timeout=10)
+            response = requests.get(url, timeout=20)
             if response.status_code != 200:
                 broken_urls.append(url)
         except requests.exceptions.RequestException: