message: Update docs for Consumer
diff: @@ -872,6 +872,8 @@ impl Consumer {
  /// this can be used to request a single message, and wait forever for a response.
  /// If you require specifying the batch size or using a timeout while consuming the
  /// responses, use the `pull_opt` method below.
  + ///
  + /// Requires the `jetstream` feature.
  pub fn pull(&mut self) -> io::Result<Message> {
  let ret_opt = self
  .pull_opt(NextRequest {
  @@ -894,6 +896,8 @@ impl Consumer {
  /// this can be used to request a configurable number of messages, as well as specify
  /// how the server will keep track of this batch request over time. See the docs for
  /// `NextRequest` for more information about the options.
  + ///
  + /// Requires the `jetstream` feature.
  pub fn pull_opt(
  &mut self,
  next_request: NextRequest,
  