Limit Kotlin API documentation to Kotlin-specific APIs

[wilkinsona]

Currently, our Kotlin API documentation includes the module's entire API, both Java and Kotlin. We should limit it to just the Kotlin-specific APIs as Framework does.

[ryuu9505]

Hi @wilkinsona,

I'd like to work on this issue. I'll follow Spring Framework's approach and filter the Kotlin docs to only include Kotlin-specific APIs.

My plan:

1. Check Spring Framework's Dokka configuration
2. Apply the same filtering to Spring Boot modules
3. Test the documentation generation locally

Let me know if there's anything specific I should keep in mind.

Thanks.

[wilkinsona]

Thanks, @ryuu9505. It's all yours.