Updates Readme examples
Updates Readme examples

The following syntax is invalid: 'pool_identity 'SpecificUser'. This pull request clarifies that you must use the following syntax: 'pool_identity :SpecificUser'
visioncritical/iis,spuder/iis,blairham/iis,sneal/iis,opscode-cookbooks/iis,jonathanmorley/iis,owen/iis,juliandunn/iis,cvent/iis,chef-cookbooks/iis,mohitsethi/chef-iis,criteo-forks/iis,drpebcak/iis