message: fixed copy/paste mistake
diff: ### Tutorial
  - Step #1 - [Lexing](https://github.com/SAP/chevrotain/blob/master/docs/tutorial/step1_lexing.md).
  -- Step #2 - [Parsing](https://github.com/SAP/chevrotain/blob/master/docs/tutorial/step1_lexing.md).
  +- Step #2 - [Parsing](https://github.com/SAP/chevrotain/blob/master/docs/tutorial/step2_parsing.md).
  - Step #3 - [Adding actions (semantics)](https://github.com/SAP/chevrotain/blob/master/docs/tutorial/step3_adding_actions_root.md).
  * [**Separately** from the grammar, using a Concrete Syntax Tree visitor](https://github.com/SAP/chevrotain/blob/master/docs/tutorial/step3a_adding_actions_visitor.md).
  * [Using **embbeded** actions inside the grammar](https://github.com/SAP/chevrotain/blob/master/docs/tutorial/step3b_adding_actions_embedded.md).
  