documentation

Pull request #2649: Feature/ZBX-26121 7.3 D

Merge in WEB/documentation from feature/ZBX-26121-7.3-D to release/7.4

* commit '9b26438f1ad1d7c99af690f91707a9ede54cf2ba':
  ZBX-26121 added a correct query_time value.
  ZBX-26121 updated JSON examples.