Add comment to document the use of the variables in the signed build yml
Add comment to document the use of the variables in the signed build yml

eriawan/roslyn,agocke/roslyn,KevinRansom/roslyn,shyamnamboodiripad/roslyn,AmadeusW/roslyn,KirillOsenkov/roslyn,AlekseyTs/roslyn,jmarolf/roslyn,diryboy/roslyn,weltkante/roslyn,eriawan/roslyn,KirillOsenkov/roslyn,physhi/roslyn,gafter/roslyn,aelij/roslyn,shyamnamboodiripad/roslyn,AmadeusW/roslyn,jmarolf/roslyn,panopticoncentral/roslyn,dotnet/roslyn,eriawan/roslyn,bartdesmet/roslyn,panopticoncentral/roslyn,diryboy/roslyn,dotnet/roslyn,aelij/roslyn,tannergooding/roslyn,brettfo/roslyn,weltkante/roslyn,jmarolf/roslyn,genlu/roslyn,tmat/roslyn,heejaechang/roslyn,davkean/roslyn,abock/roslyn,sharwell/roslyn,brettfo/roslyn,aelij/roslyn,agocke/roslyn,bartdesmet/roslyn,dotnet/roslyn,weltkante/roslyn,brettfo/roslyn,mgoertz-msft/roslyn,AmadeusW/roslyn,agocke/roslyn,heejaechang/roslyn,tmat/roslyn,AlekseyTs/roslyn,ErikSchierboom/roslyn,gafter/roslyn,stephentoub/roslyn,reaction1989/roslyn,wvdd007/roslyn,wvdd007/roslyn,genlu/roslyn,jasonmalinowski/roslyn,physhi/roslyn,ErikSchierboom/roslyn,davkean/roslyn,sharwell/roslyn,ErikSchierboom/roslyn,wvdd007/roslyn,KirillOsenkov/roslyn,abock/roslyn,AlekseyTs/roslyn,KevinRansom/roslyn,stephentoub/roslyn,physhi/roslyn,bartdesmet/roslyn,reaction1989/roslyn,shyamnamboodiripad/roslyn,stephentoub/roslyn,tannergooding/roslyn,mgoertz-msft/roslyn,mavasani/roslyn,CyrusNajmabadi/roslyn,panopticoncentral/roslyn,tmat/roslyn,mavasani/roslyn,mgoertz-msft/roslyn,gafter/roslyn,sharwell/roslyn,reaction1989/roslyn,genlu/roslyn,jasonmalinowski/roslyn,tannergooding/roslyn,davkean/roslyn,diryboy/roslyn,mavasani/roslyn,abock/roslyn,CyrusNajmabadi/roslyn,KevinRansom/roslyn,jasonmalinowski/roslyn,heejaechang/roslyn,CyrusNajmabadi/roslyn