Workload characterization of MLPerf HPC benchmarks

Instructions to perform memory, I/O and network bandwidthe measurements of MLPerf HPC benchmarks used in v0.7 submission round across different HPC systems.

The steps correspond to our paper "MLPerf^TM HPC: A Holistic Benchmark Suite forScientific Machine Learning on HPC Systems" accepted at the Workshop on Machine Learning in HPC Environments (MLHPC) at Supercomputing 2021.