documentation

Pull request #741: Feature/ZBXNEXT-6796 6.4 D

Merge in WEB/documentation from feature/ZBXNEXT-6796-6.4-D to release/6.4

* commit 'dd6b7b6dfd7738a7985fa3bf9599dc33a32eb30a':
  [ZBXNEXT-6796] replacing screenshot
  [ZBXNEXT-6796] additional fixes
  [ZBXNEXT-6796] notification macros in alert scripts
  [ZBXNEXT-6796] alert scripts support all notification macros
  [ZBXNEXT-6796] updated media type script page
  deleted unneeded empty pages (DokuWiki leftover)
  Deleted empty pages