documentation

Pull request #758: Feature/ZBX-22334 6.4 D

Merge in WEB/documentation from feature/ZBX-22334-6.4-D to release/6.4

* commit 'a0f26ab8812c9084306dcac545149169b8d8a630':
  ZBX-22334 Edited noteimportant.
  ZBX-22334 Corrected grammar.
  ZBX-22334 Edited image and added note.
  ZBX-22334 Edited text and formatting.
  ZBX-22334 Edited formatting and punctuation.
  ZBX-22334 Added info on Web monitoring widget.