message: Update token_grouping.md
diff: # Token Grouping
  Chevrotain lexers support grouping Tokens Types **separately** from the main token vector in the lexing result.
  -This is often useful to **collect** a specific set of Token Types for later processing most commonly to collect comments tokens.
  +This is often useful to **collect** a specific set of Token Types for later processing, for example to collect comments tokens.
  To group a Token Type simply specify the [**group**](https://sap.github.io/chevrotain/documentation/4_0_0/interfaces/itokenconfig.html#group) property in its configuration.
  For example:
  