documentation

Pull request #3469: ZBXNEXT-9546 updated screenshots, added description for new options.

Merge in WEB/documentation from feature/ZBXNEXT-9546-7.5-D to release/8.0

* commit 'c714b3131cfa989cbb021cff7b338186b193846a':
  ZBXNEXT-9546 formatting.
  ZBXNEXT-9546 added missing parameters and an api changes entry.
  ZBXNEXT-9546 formatting.
  ZBXNEXT-9546 added new properties.
  ZBXNEXT-9546 added missing period, corrected parameter descriptions.
  ZBXNEXT-9546 formatting.
  ZBXNEXT-9546 updated JSON exapmles.
  ZBXNEXT-9546 updated a what's new entry, screenshots, tags tab description, added missing parameters, API changes entries, tags tab description.
  ZBXNEXT-9546 added a what's new entry.
  ZBXNEXT-9546 formatting.
  ZBXNEXT-9546 updated a screenshot, added new parameters, added info about tags, added a widget field.
  ZBXNEXT-9546 updated screenshots, added description for new options.