Add tests, fix the directions and missing attributes.

[ahmedcharles]

The referenced article, multiple datasheets and local testing all suggest that the directions should be reversed.

[leshow]

Sorry I have not used this crate in some time, but do you mean this article? https://www.best-microcontroller-projects.com/rotary-encoder.html

I believe I got the directions from this section:

Is that not how it is already implemented? In any case, I'm not sure it would be responsible to merge a direction change at this point as anyone using the crate and updating could have counted on the direction being a specific way already.

[ahmedcharles]

Indeed, a is LSB and b is MSB, which was switched in the original implementation, probably to match the original implementation.

[ahmedcharles]

Anyways, would you like the tests without the direction change?

[leshow]

@ahmedcharles I see. Yeah, thanks! I'll take the tests

[ahmedcharles]

Thanks.