Add more build/run information to README.MD

The way README.MD describes the build/run process is useless. Change it to a batter one. See https://github.com/hpc-fci-mackenzie/desafio-erad-sp-2018/tree/dev ; https://github.com/hpc-fci-mackenzie/erad-rs-2019 ; or any other better description (https://gitlab.cern.ch/VecGeom/VecGeom/blob/master/README.md and https://gitlab.cern.ch/VecGeom/VecCore/blob/master/README.md).