Update Pandoc output format to 'gfm+attributes' in MkDocs hook

mkdocs/hooks/pandoc-to-mkdocs.py

@@ -10,7 +10,7 @@ def on_page_markdown(markdown: str, page, config, files) -> str | None:
     cmd = [
         "pandoc",
         f"--lua-filter={lua_filter_path}",
-        "--to", "gfm"
+        "--to", "gfm+attributes"
     ]
 
     try: