Simple-ZCU111-Example Documentation

Reference RFSoC ADC/DAC firmware and software example for the Xilinx ZCU111 evaluation board (Xilinx Zynq UltraScale+ RFSoC, FPGA part xczu28dr-ffvg1517-2-e). Built on the SLAC axi-soc-ultra-plus-core platform; shared workflow documentation lives on the platform docs site.