message: docs: fix typo word 'occurrance' in operators doc
diff: @@ -282,7 +282,7 @@ function discardOddDoubleEven() {
  ### Creating new operators from scratch
  -It is more complicated, but if you have to write an operator that cannot be made from a combination of existing operators (a rare occurrance), you can write an operator from scratch using the Observable constructor, like this:
  +It is more complicated, but if you have to write an operator that cannot be made from a combination of existing operators (a rare occurrence), you can write an operator from scratch using the Observable constructor, like this:
  ```ts
  import { Observable, of } from 'rxjs';
  