Follow up changes in documentation after #28927

[kvch]

What does this PR do?

This PR adds the missing documentation changes after the removal of suffix option from logging.

Why is it important?

To let users know what's what. :D

Checklist

- [ ] My code follows the style guidelines of this project
- [ ] I have commented my code, particularly in hard-to-understand areas

• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
  - [ ] I have added tests that prove my fix is effective or that my feature works
  - [ ] I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

[mergify]

This pull request does not have a backport label. Could you fix it @kvch? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v./d./d./d is the label to automatically backport to the 7./d branch. /d is the digit

NOTE: backport-skip has been added to this pull request.

[elasticmachine]

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• Start Time: 2021-12-17T15:42:45.867+0000

• Duration: 133 min 36 sec

• Commit: 7e31862

Test stats 🧪

Test	Results
Failed	0
Passed	48649
Skipped	4277
Total	52926

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