New supported device: MT09R NU1 Indoor Ceiling Cassette + MU4R25 U21 Outdoor Device

[mptr8956]

Installed the first controller today, works flawlessly with the indoor device.

Thank you very much, awesome project! :)

[JanM321]

Thanks! I've added the unit to the README.

Most people are using this controller with wall mounted indoor units so it's always good to hear it works with other types too.