documentation

Pull request #4393: Feature/ZBXNEXT-10611 7.5 D

Merge in WEB/documentation from feature/ZBXNEXT-10611-7.5-D to release/8.0

* commit '03bf52170907531d0874419d43dc3e24e6052217':
  ZBXNEXT-10611 a fix to a JSON example.
  ZBXNEXT-10611 removed redundant pages, added a what's new entry.
  ZBXNEXT-10611 added new field name to an example, created what's new pages an an entry.