provider/vsphere: Reword customizations docs

Author: jen20

website/source/docs/providers/vsphere/index.html.markdown

@@ -109,23 +109,28 @@ and [vSphere
 For additional information on roles and permissions, please refer to official
 VMware documentation.
 
-## Customizations
+## Virtual Machine Customization
 
-This provider use
+Guest Operating Systems can be configured using
 [customizations](https://pubs.vmware.com/vsphere-50/index.jsp#com.vmware.vsphere.vm_admin.doc_50/GUID-80F3F5B5-F795-45F1-B0FA-3709978113D5.html),
-this resource is used to configure guest operation system (Domain, hostname,
-etc..). The problem to work with this customizations are that only a certain OS
-are accepted. The list of accepted OS are
+in order to set things properties such as domain and hostname. This mechanism
+is not compatible with all operating systems, however. A list of compatible
+operating systems can be found
 [here](http://partnerweb.vmware.com/programs/guestOS/guest-os-customization-matrix.pdf)
 
-
-If the system are not in the list of the Supported OS, terraform will create a
-server but will fail with the following error
+If customization is attempted on an operating system which is not supported, Terraform will
+create the virtual machine, but fail with the following error message:
 
 ```
-Customization of the guest operating system 'debian6_64Guest' is not supported in this configuration. Microsoft Vista (TM) and Linux guests with Logical Volume Manager are supported only for recent ESX host and VMware Tools versions. Refer to vCenter documentation for supported configurations.
+Customization of the guest operating system 'debian6_64Guest' is not
+supported in this configuration. Microsoft Vista (TM) and Linux guests with
+Logical Volume Manager are supported only for recent ESX host and VMware Tools
+versions. Refer to vCenter documentation for supported configurations.  ```
 ```
 
+In order to skip the customization step for unsupported operating systems, use
+the `skip_customization` argument on the virtual machine resource.
+
 ## Acceptance Tests
 
 The VMware vSphere provider's acceptance tests require the above provider