Updating history.md to mention change in error recovery return value.
`context.state.actions.keys()` but in the context of GLR
`error.symbols_expected` will give a subset of all possible symbols in the
given state for which parser is guaranteed to continue (e.g. to execute
- SHIFT).
+ SHIFT). error_recovery now returns (token, position) tuple.
- Error recovery function now returns token and position. The error is
automatically registered and returned with parsing results.
- `custom_lexical_disambiguation` parser param/callback changed to
