runner: Improve Pipeline.model_id comment

runner/app/pipelines/base.py

@@ -5,7 +5,7 @@
 class Pipeline(ABC):
     @abstractmethod
     def __init__(self, model_id: str, model_dir: str):
-        self.model_id: str # type hint so we can use the field in routes
+        self.model_id: str # declare the field here so the type hint is available when using this abstract class
         raise NotImplementedError("Pipeline should implement an __init__ method")
 
     @abstractmethod