Support button click

[dereulenspiegel]

It would be really cool if this library would support "clickable" rotary encoders. The corresponding arduino library (like https://github.com/0xPIT/encoder/tree/arduino) supports detection of Click, DoubleClick, Held and Release.
If this is in the scope of this project, this would probably help a little bit in the transition from arduino to rust projects.

[leshow]

Sure! I don't see why we couldn't support something like that. It might help to put it behind a feature gate.

[ahmedcharles]

Note, clickable encoders use different pins to detect clicks than the ones used by the encoder, so I'm not sure there's much benefit to joining them. Also, there are encoders that have 5 switches (https://www.adafruit.com/product/5001) which would suggest having to support an arbitrary number of switches.