message: docs(examples): Fix typo in client_json example comment
  Fixes typo on comment about error types in client_json example.
diff: @@ -64,7 +64,7 @@ struct User {
  name: String,
  }
  -// Define a type so we can return multile types of errors
  +// Define a type so we can return multiple types of errors
  enum FetchError {
  Http(hyper::Error),
  Json(serde_json::Error),
  