documentation

Pull request #1655: feature/ZBXNEXT-8853-7.0-D. Synchronized notification snooze across user sessions.

Merge in WEB/documentation from feature/ZBXNEXT-8853-7.0-D to release/7.0

* commit '3bc73a3395f4b845783f16332db762baca8cf975':
  Clarified note on autoplay of sounds
  [ZBXNEXT-8853] Synchronized notification snooze across user sessions
  Refined formatting (screenshot size, italics, etc.)
  Refined page wording & grammar
  Made line breaks pretty & handy for translations
  [ZBXNEXT-8853] Synchronized notification snooze across user sessions