### Added

- `LevelFilter` type and `LevelFilter::current()` for returning the
  highest level that any subscriber will enable (#853)
- `Subscriber::max_level_hint` optional trait method, for setting the
  value returned by `LevelFilter::current()` (#853)

### Fixed

- **docs**: Removed outdated reference to a Tokio API that no longer exists
  (#857)

Thanks to new contributor @dignati for contributing to this release!

Signed-off-by: Eliza Weisman <eliza@buoyant.io>