documentation

Pull request #3278: Feature/ZBX-16777 7.5 D

Merge in WEB/documentation from feature/ZBX-16777-7.5-D to release/8.0

* commit 'f8aef012fecfe6a56baf2f37ea8f6890137a4f9d':
  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.