compute.md in fog-azure-rm-0.2.0

- old
+ new

@@ -15,17 +15,24 @@
 Next, create a connection to the Compute Service:
 
 ```ruby
     azure_compute_service = Fog::Compute.new(
         provider: 'AzureRM',
-        tenant_id: '<Tenantid>',                  # Tenant id of Azure Active Directory Application
-        client_id:    '<Clientid>',               # Client id of Azure Active Directory Application
-        client_secret: '<ClientSecret>',          # Client Secret of Azure Active Directory Application
-        subscription_id: '<Subscriptionid>'       # Subscription id of an Azure Account
+        tenant_id: '<Tenantid>',                                                          # Tenant id of Azure Active Directory Application
+        client_id:    '<Clientid>',                                                       # Client id of Azure Active Directory Application
+        client_secret: '<ClientSecret>',                                                  # Client Secret of Azure Active Directory Application
+        subscription_id: '<Subscriptionid>',                                              # Subscription id of an Azure Account
+        :environment => '<AzureCloud/AzureChinaCloud/AzureUSGovernment/AzureGermanCloud>' # Azure cloud environment. Default is AzureCloud.
 )
 ```
 
+## Check Server Existence
+
+```ruby
+azure_compute_service.servers.check_vm_exists(<Resource Group name>, <VM Name>)
+```
+
 ## Create Server
 
 Create a new linux server
 
 ```ruby
@@ -131,10 +138,16 @@
 
 ```ruby
       server.destroy
 ```
 
+## Check Availability Set Existence
+
+```ruby
+azure_compute_service.availability_sets.check_availability_set_exists(<Resource Group name>, <Availability Set name>)
+```
+
 ## Create Availability Set
 
 Create a new availability set
 
 ```ruby
@@ -171,9 +184,15 @@
 
 Get an availability set object from the get method and then destroy that availability set.
 
 ```ruby
       availability_set.destroy
+```
+
+## Check Virtual Machine Extension Existence
+
+```ruby
+azure_compute_service.virtual_machine_extensions.check_vm_extension_exists(<Resource Group name>, <Virtual Machine Name>, <Extension Name>)
 ```
 
 ## Create Virtual Machine Extension
 
 Installs an extension to the specified virtual machine.