message: Update docs about pitfalls of cache and V8 hidden classes.
  Fixes
diff: @@ -222,6 +222,16 @@ These are highly recommended for each and every parser.
  })
  ```
  + - Avoid dynamically changing the parser instance. The line:
  + > "$.c1 || ($.c1 = ..." ($ is 'this')
  +
  + Will cause a 'c1' property to be assigned to the parser instance.
  + This may seem innocent but if enough properties are added dynamically to an instance
  + its V8 hidden class will change which could cause a severe performance reduction.
  +
  + To avoid this, simpliy define these "cache properties" in the constructor.
  + See an example in the [ECMAScript5 grammar's constructor](https://github.com/SAP/chevrotain/blob/ac21570b97a8de0d6b91f29979aed8041455cacd/examples/grammars/ecma5/ecma5_parser.js#L37-L43).
  +
  #### Minor Performance Benefits
  