KAi: Plugins support

## Definition of done
- Update the table here in the Gateway Config row to include plugins: https://developer.konghq.com/konnect-platform/kai/#what-s-new-in-kai
- Update the changelog here (https://developer.konghq.com/konnect-platform/kai/#what-s-new-in-kai) and here (https://developer.konghq.com/konnect-platform/kai/changelog/)

## Information
Aha: https://konghq.aha.io/epics/KAI-E-10
DRP: Sumeetha S.

## Due date (optional)

March 2026 “scope & dates are not confirmed. Most likely not in Feb”

## Size
XS

Open the KAi “What’s New” page linked in the issue and the linked changelog page. Locate the Gateway Config table row and the changelog sections, update both requested locations to mention plugins, then verify the rendered table and changelog show the addition.

Written by the indexing model from the issue text.