update readme to include information on IQ demodulation
update readme to include information on IQ demodulation

jniemann66/ReSampler,jniemann66/ReSampler,jniemann66/ReSampler,jniemann66/ReSampler,jniemann66/ReSampler,jniemann66/ReSampler,jniemann66/ReSampler,jniemann66/ReSampler