documentation

Pull request #1877: feature/ZBX-23951-6.0-D: Added details on template format.

Merge in WEB/documentation from feature/ZBX-23951-6.0-D to release/6.0

* commit 'd52ca6f0ce18a3fe14061a2df8a28dc8732bad6d':
  [ZBX-23951] Adjusted wording
  [ZBX-23951] Added details on template format