Improve vulnerability deduplication docs

What does this MR do and why?

We should not expect users to read the source code to understand how the application should behave. This MR improves the documentation so that it describes the behavior directly instead of directing the reader to the code.

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.