update vcenter_vm_hardware_disk description (#548)

SUMMARY
Fixes #469
Mention the new disks type in the module description, since mentioned elsewhere
ISSUE TYPE

Docs Pull Request

COMPONENT NAME
vcenter_vm_hardware_disk

Reviewed-by: Anna Savina

changelogs/fragments/548-update-docs-for-vm-harware-disk.yml

@@ -0,0 +1,3 @@
+---
+trivial:
+  - vcenter_vm_hardware_disk - Updated description to explicitly mention that the disk type is thin

config/modules.yaml

@@ -151,6 +151,9 @@
 - vcenter_vm_hardware_cpu:
 - vcenter_vm_hardware_disk_info:
 - vcenter_vm_hardware_disk:
+    documentation:
+      short_description: Adds a thin provisioned virtual disk to the virtual machine
+      description: Adds a virtual disk to the virtual machine. The disk (provision) type is always 'thin'. While adding the virtual disk, a new VMDK file may be created or an existing VMDK file may be used to back the virtual disk.
 - vcenter_vm_hardware_ethernet_info:
 - vcenter_vm_hardware_ethernet:
 - vcenter_vm_hardware_floppy_info:

plugins/modules/vcenter_vm_hardware_disk.py

@@ -9,10 +9,10 @@
 
 DOCUMENTATION = r"""
 module: vcenter_vm_hardware_disk
-short_description: Adds a virtual disk to the virtual machine
-description: Adds a virtual disk to the virtual machine. While adding the virtual
-    disk, a new VMDK file may be created or an existing VMDK file may be used to back
-    the virtual disk.
+short_description: Adds a thin provisioned virtual disk to the virtual machine
+description: Adds a virtual disk to the virtual machine. The disk (provision)
+    type is always 'thin'. While adding the virtual disk, a new VMDK file may
+    be created or an existing VMDK file may be used to back the virtual disk.
 options:
     backing:
         description: