sap_vm_provision: append vmware notes

[sean-freeman]

For PLATFORM_GUIDANCE.md....

Change broken URL:
https://developer.vmware.com/docs/18555/GUID-75E27FA9-2E40-4CBF-BF3D-22DCFC8F11F7.html

To equiv:
https://techdocs.broadcom.com/us/en/vmware-cis/vsphere/vsphere-sdks-tools/8-0/web-services-sdk-programming-guide/virtual-machine-guest-operations/guest-customization-using-cloud-init.html

And add reference URLs:

• https://knowledge.broadcom.com/external/article/311895/how-to-customize-virtual-machine-using-c.html
• https://developer.broadcom.com/xapis/vsphere-automation-api/latest/vcenter/data-structures/Guest_CloudinitConfiguration/
• https://knowledge.broadcom.com/external/article/311864/how-does-vsphere-guest-os-customization.html

Question:

• Is perl required for VMware Customization to trigger cloud-init? Should be installed by default in OS Images anyway?

[marcelmamula]

@sean-freeman PR was created for document update in #115

perl is not required for cloud-init so I left it only at document update (perl is preinstalled on both SLES 15 and 16).

[marcelmamula]

Closing as change was made in #115 and released with 1.3.0