[max] Update Readme (#3661)
[max] Update Readme (#3661)

- Correct Thing definition example
- Include example for Shutter contact
- Update Item definition example with shutter contact and UoM

Signed-off-by: David Kalwar <1f48fb6280200c840504e5de96160156c05e1552@gmail.com> (github: chiefymuc)

Snickermicker/openhab2,theoweiss/openhab2,theoweiss/openhab2,trokohl/openhab2-addons,clinique/openhab2,trokohl/openhab2-addons,digitaldan/openhab2,Snickermicker/openhab2,trokohl/openhab2-addons,tavalin/openhab2-addons,clinique/openhab2,lewie/openhab2,gerrieg/openhab2,tavalin/openhab2-addons,jarlebh/openhab2-addons,theoweiss/openhab2,jarlebh/openhab2-addons,Snickermicker/openhab2,aogorek/openhab2-addons,tavalin/openhab2-addons,afuechsel/openhab2,lewie/openhab2,aogorek/openhab2-addons,tavalin/openhab2-addons,aogorek/openhab2-addons,gerrieg/openhab2,aogorek/openhab2-addons,afuechsel/openhab2,digitaldan/openhab2,jarlebh/openhab2-addons,gerrieg/openhab2,digitaldan/openhab2,jarlebh/openhab2-addons,lewie/openhab2,aogorek/openhab2-addons,trokohl/openhab2-addons,Snickermicker/openhab2,clinique/openhab2,jarlebh/openhab2-addons,clinique/openhab2,tavalin/openhab2-addons,trokohl/openhab2-addons,tavalin/openhab2-addons,theoweiss/openhab2,gerrieg/openhab2,aogorek/openhab2-addons,digitaldan/openhab2,trokohl/openhab2-addons,afuechsel/openhab2,jarlebh/openhab2-addons