message: docs(operator-creation): fix a typo
diff: @@ -111,7 +111,7 @@ Hopefully the information provided here will give context to decisions made whil
  There are a few things to know and (try to) understand while developing operators:
  1. All operator methods are actually created in separate modules from `Observable`. This is so developers can
  - "build their own observable" by pulling in operator methods an adding them to observable in their own module.
  + "build their own observable" by pulling in operator methods and adding them to observable in their own module.
  It also means operators can be brought in ad-hock and used directly, either with the ES7 function bind operator
  in Babel (`::`) or by using it with `.call()`.
  2. Every operator has an `Operator` class. The `Operator` class is really a `Subscriber` "factory". It's
  