Added basic client usage in Readme

README.md

@@ -24,7 +24,21 @@ Or install it yourself as:
 
 ## Usage
 
-TODO: Write usage instructions here
+To get basic information from the virtual appliance
+
+```ruby
+require 'xclarity_client'
+
+conf = XClarityClient::Configuration.new(
+  :username => 'admin',
+  :password => 'pass',
+  :host     => 'http://example.com'
+)
+
+virtual_appliance = XClarityClient::VirtualApplianceManagement.new(conf)
+
+puts virtual_appliance.configuration_settings
+```
 
 ## Development