Update class_diagram_generator.py

class_diagram_generator.py

@@ -333,7 +333,7 @@ def generate_class_diagram(json_input: str, output_format: str) -> str:
     }
 
     Returns:
-        str: The filepath to the generated PNG image file.
+        str: The filepath to the generated image file.
     """
     try:
         if not json_input.strip():