Reorganize Kubernetes documentation

[zc-devs]

Currently there are two pages with Kubernetes documentation: 80-kubernetes.md and 40-kubernetes.md.

It may confuse contributors as they don't know which one they should edit.

It may confuse users as it's more difficult to find information. Even after knowing about changes (#1896), it took some time to find it on the site.

I purpose to:

1. Move Volumes to 40-kubernetes.md;
2. All other stuff to Installation section of 00-setup.md like docker-compose. Or make it subpage inside Administration-Setup.