documentation

Pull request #2106: feature/ZBXNEXT-9588-7.2-D. subsystem support for ssh.run[] item.

Merge in WEB/documentation from feature/ZBXNEXT-9588-7.2-D to release/7.2

* commit '9f2b62ffa1a894f4064027545cb5abc8715d39e4':
  [ZBXNEXT-9588] subsystem support for ssh.run[] item (updated wording, examples)
  [ZBXNEXT-9588] subsystem support for ssh.run[] item