Add operations guide and upgrade procedures documentation

Operations guide:
 - verification of correct deployment and operation
 - verification of configuration validity
 - management of OSH components (containers, container images, jobs, kubernetes cluster, others)
 - management of networking, IPv6
 - management of databases, DNS, service discovery and MQ services
 - management of logs
 - management of storage
 - maintaining high availability
 - monitoring health of components
 - recovering from components failures
 - collecting information and requesting support/submitting bug reports
 - management automation
 - scaling clusters up and down
 - performance tuning
 - backups and backup tests
 - restore to BAU from backup
 - disaster recovery planning, implementation, and tests
 - security considerations, aaa, rbac, network security, etc.
 - customization and add-ons

Upgrade, update, migration guide:
 - components versioning and compatibility
 - preparation tasks (backups, test on cloned clusters, etc.)
 - applying hot fixes/minor updates
 - major upgrades/migrations procedure