message: Improve `Event::parents` RustDoc
diff: @@ -238,8 +238,11 @@ impl<'event, 'meta: 'event> Event<'event, 'meta> {
  DebugFields(self)
  }
  - /// Returns an iterator over all the [`Span`]s that are parents of this
  - /// `Event`.
  + /// Returns an iterator over [`SpanData`] references to all the [`Span`]s
  + /// that are parents of this `Event`.
  + ///
  + /// The iterator will traverse the trace tree in ascending order from this
  + /// event's immediate parent to the root span of the trace.
  pub fn parents<'a>(&'a self) -> Parents<'a> {
  Parents {
  next: Some(&self.parent),
  