Added explicit build command for Windows and clarification on obtaining (#70190)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70190
C++ build tools to readme.md
Test Plan: Imported from OSS
Reviewed By: jbschlosser
Differential Revision: D33245438
Pulled By: ikriv
fbshipit-source-id: ef863d68926bd7416d0e10d24197d19392c124de
