documentation

Pull request #3262: Feature/ZBX-16777 7.0 D

Merge in WEB/documentation from feature/ZBX-16777-7.0-D to release/7.0

* commit '91064f05d867c598f96c2beae65d50e4001f1f07':
  ZBX-16777 updated the instructions. Removed redundant sections.
  ZBX-16777 formatting, removed redundant symbols.
  ZBX-16777 changed an ampersand to a word,
  ZBX-16777 fixed a comment block.
  ZBX-16777 added instructions.
  ZBX-16777 initial draft.
  ZBX-16777 formatting.