documentation

Pull request #2234: Feature/ZBX-23960 6.0 D c5

Merge in WEB/documentation from feature/ZBX-23960-6.0-D-c5 to release/6.0

* commit '3ec6299afff154a3481d7dd99c566bcd4aea1fb2':
  ZBX-23960 the description of the "Message" column has been clarified.
  ZBX-23960 fixed broken link.
  ZBX-23960 corrected available choices and displayed operation types.