Update key in documentation for secret_detection

What does this MR do?

This key in documentation seems to be not working. Maybe out of date ?

I don't really have time to check all acceptance criteria, but opening a MR seems to be a little better than opening an issue.

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers