Update crossgen.md
authorFadi Hanna <fadim@microsoft.com>
Thu, 13 Jun 2019 21:59:12 +0000 (14:59 -0700)
committerGitHub <noreply@github.com>
Thu, 13 Jun 2019 21:59:12 +0000 (14:59 -0700)
commitc5c68b13bbf08d9047b1a894df5fe7f8bb3d239d
tree8c0fabc7eaaaedf621dad385043899e50d8af33d
parenta8f832b54f6e5db551de9427aea040da2bf4ca66
Update crossgen.md

Add instructions on how to use the /r switch. Update instructions to use /p instead of /Platform_Assemblies_Paths (shorter version)
Documentation/building/crossgen.md