docs(flow): remove extra param in base docs (#1838)

* docs(flow): remove extra param

* docs(flow): format docs

jina/flow/base.py

@@ -175,7 +175,7 @@ def needs(self, needs: Union[Tuple[str], List[str]],
     def needs_all(self, name: str = 'joiner', *args, **kwargs) -> FlowLike:
         """
         Collect all hanging Pod so far and add a blocker to the flow, wait until all handing peas completed.
-        :param copy_flow: when set to true, then always copy the current flow and do the modification on top of it then return, otherwise, do in-line modification
+        
         :param name: the name of this joiner, by default is ``joiner``
         :return: the modified flow
         """