Add nuget.config file

Add nuget.config file because it contains secret data and should be kept localy

Author: parsalotfy

VisualStudio.gitignore

@@ -205,6 +205,9 @@ PublishScripts/
 *.nuget.props
 *.nuget.targets
 
+# Nuget personal access tokens and Credentials
+nuget.config
+
 # Microsoft Azure Build Output
 csx/
 *.build.csdef