Upgrade guide about upgrade to GWAPI v1.1 and KIC v3.2

[tao12345666333]

Is there an existing issue for this?

• I have searched the existing issues

Does this enhancement require public documentation?

• I have added an Acceptance Criteria item for adding and/or adjusting public documentation (if applicable)

Problem Statement

In KIC v3.2, we have upgraded the Gateway API to version v1.1. #5705 (comment)
However, there are a series of updates in Gateway API v1.1, including GA for GRPCRoute.

So in KIC 3.2, users can directly use GRPCRoute v1.

However, during the upgrade process, we need to address how to upgrade the GRPCRoute from version v1alpha2 to v1, how to upgrade the CRD of Gateway API, and how to upgrade KIC. We need a guide document for this.

Proposed Solution

• Add a new guide for the upgrade

Additional information

No response

Acceptance Criteria

• There is an upgrade guide that guides users on how to upgrade the Gateway API to v1.1 and work with KIC v3.2.

[tao12345666333]

Kong/docs.konghq.com#7503 has been merged, let me close this ione