documentation

Pull request #2912: feature/DEV-4228-7.3-D-sec. OpenSSL best practice when building agent.

Merge in WEB/documentation from feature/DEV-4228-7.3-D-sec to release/7.4

* commit 'a24c4f6d2be743be5d2acb9db083bbb504592042':
  [DEV-4228] updated wording
  [DEV-4228] updated directories
  [DEV-4228, ZBXI-1520] clarified OpenSSL best practice when building agent