Add info on how to provide CONJUR_* variables in Windows environment

[mdzieciol]

PS C:\Users\marcin.dzieciol\Downloads> C:\Users\marcin.dzieciol\Downloads\summon.exe --yaml 'pass: !var pass' .\pass.ps1
Error fetching variable pass: exit status 1: level=error msg="Failed creating a Conjur client: Must specify an ApplianceURL -- Must specify an Account\n"

I have a problem with providing conjur communication variables in windows. All instructions in README is related to unix environment. Can you add info about Windows configuration?