R. Yin

Make `tokio::io::Stdin` implement lines methods, like `std::io::Stdin`

1

**Is your feature request related to a problem? Please describe.** std::io::Stdin implements methods that allow reading one line at a time from Stdin. These methods don't exist on tokio::io::Stdin **Describe...

The current code returns false unconditionally, which is inconsistent with the [Python driver](https://github.com/pimoroni/trackball-python/blob/master/library/trackball/__init__.py#L101-L107). Changed to make it return value