documentation

Pull request #1749: feature/ZBX-24291-7.0-D. Added note on RHEL package limitations.

Merge in WEB/documentation from feature/ZBX-24291-7.0-D to release/7.0

* commit 'd5dc14c1209b58c15a146be5e77cb803ece4cb3d':
  [ZBX-24291] fixed link
  [ZBX-24291] added a more detailed "Known issues" entry on RHEL package limitations
  [ZBX-24291] added note on RHEL package limitations