Update installation.md
Update installation.md

Put the gitversion command for .net core cli into the doc, since i can never find it and never remember it
asbjornu/GitVersion,gep13/GitVersion,GitTools/GitVersion,ermshiperete/GitVersion,ermshiperete/GitVersion,GitTools/GitVersion,asbjornu/GitVersion,gep13/GitVersion,ermshiperete/GitVersion,ermshiperete/GitVersion