documentation

.D........ [DEV-2201, ZBX-19118] added missing 6.0 page and API changes in discoveryrule, item and itemprototype

Merge in WEB/documentation from feature/DEV-2201-6.0-D to release/6.0

* commit '5ef6bc158c5d52257163c4d5bad0cfddb31bfaf2':
  .D........ [DEV-2201] fixed incorrect examples
  .D........ [DEV-2201] fixed wording, examples and added missing type
  [DEV-2201] updated examples, fixed formatting
  [DEV-2201, ZBX-19118] updated examples, fixed formatting
  [DEV-2201, ZBXNEXT-6923] fixed wording
  [DEV-2201] fixed formatting
  [DEV-2201, ZBX-19118] removed extra colons
  [DEV-2201, ZBX-19118] added missing API changes in discoveryrule, item and itemprototype; updated examples
  .D........ [DEV-2201] fixed incorrect title
  .D........ [ZBXNEXT-6999, DEV-2201] added missing changes in documentation, fixed formatting to be more consistent
  .D........ [ZBXNEXT-5252, DEV-2201] added missing changes to dashboard object
  .D........ [ZBXNEXT-6923, DEV-2201] fixed formatting
  .D........ [ZBXNEXT-6923, DEV-2201] added missing changes for HA nodes in API documentation, made formatting more consistent
  .D........ [DEV-2201] fixed incorrect chronological order, incorrect description placement of API changes (should be in other API methods), other problems like naming and formatting issues
  .D........ [DEV-2201] fixed formatting to be somewhat consistent with 6.2
  .D........ [DEV-2201, ZBX-19118] added missing 6.0 page and API changes in discoveryrule, item and itemprototype