Add "Add Kolla Ansible encryption state document to SDN #62" to documentation.

[scoopex]

SovereignCloudStack/hardware-landscape#62

This documentation describes the development status for the SDN encyrption. As you can see, there are currently some Openstack change requests waiting to be integrated into Kolla-Ansible.

So that this can be tracked, it makes sense to create a new menu item ‘Technical Previews’ below https://docs.scs.community/docs/category/iaas-layer where this document is then stored.

(https://github.com/SovereignCloudStack/docs/tree/main/docs/02-iaas)