documentation

Pull request #2189: Feature/ZBX-25537 7.3 D

Merge in WEB/documentation from feature/ZBX-25537-7.3-D to release/7.4

* commit 'd8c20b3b50780090c49179db2e34bd0e1b428c15':
  ZBX-25537 improved macros description.
  ZBX-25537 item and proxy macro description for numbered item/proxy macro now correctly refer to the item; improved description clarity.