message: Update Lexing examples links
diff: A few simple examples of using the Chevrotain Lexer to resolve some common lexing problems/scenarios.
  -* [Different types of Tokens Chevrotain provides](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/token_types/token_types.js)
  +* [Different types of tokens Chevrotain provides](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/token_types/token_types.js)
  * [Keywords vs Identifiers](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/keywords_vs_identifiers/keywords_vs_identifiers.js)
  -* [Token Groups](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/token_groups/token_groups.js)
  -* [Lexer with Multiple Modes](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/multi_mode_lexer/multi_mode_lexer.js)
  -* [Custom Token Patterns implementations](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/custom_patterns/custom_patterns.js)
  +* [Token groups](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/token_groups/token_groups.js)
  +* [Lexer with multiple Modes](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/multi_mode_lexer/multi_mode_lexer.js)
  +* [Custom token patterns implementations](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/custom_patterns/custom_patterns.js)
  +* [Python Indentation handling](https://github.com/SAP/Chevrotain/blob/master/examples/lexer/python_indentation/python_indentation.js)
  to run all the lexer examples's tests:
  