doc/Invoke: Clearer "success indicator" wording for errors (#840)
doc/Invoke: Clearer "success indicator" wording for errors (#840)

A user was confused by the wording,

> If the final returned object is an error,
> it's assumed to be a success indicator.

They reasonably expect that an error is an indicator of failure.

Clarify the sentence to make it clear that the error indicates *whether*
the operation was successful.
uber-go/fx,uber-go/fx