add TODO.md for 0.12.0 release
add TODO.md for 0.12.0 release

Oh sweet silence on the issue tracker

rosenpin/Gadgetbridge,ivanovlev/Gadgetbridge,rosenpin/Gadgetbridge,Freeyourgadget/Gadgetbridge,Freeyourgadget/Gadgetbridge,roidelapluie/Gadgetbridge,ivanovlev/Gadgetbridge,Freeyourgadget/Gadgetbridge,rosenpin/Gadgetbridge,Freeyourgadget/Gadgetbridge,roidelapluie/Gadgetbridge,roidelapluie/Gadgetbridge,ivanovlev/Gadgetbridge