Add Kotlin example for logout configuration of reactive authentication

[talerngpong]

Expected Behavior

It should provide both of Java and Kotlin examples for a logout configuration of reactive authentication.

Current Behavior

It provides only a Java example.

Context

When walking through Reactive X.509 Authentication, its page contains both of Java and Kotlin examples for reactive x509 configurations by toggling. Then, after walking to its next page of Logout, there is only a Java example.

[eleftherias]

Thanks for reaching out @talerngpong.
Are you interested in submitting a pull request to add the equivalent Kotlin code to the documentation?

[talerngpong]

@eleftherias Yes, I interest submitting the relevant pull request below.

#10823

[eleftherias]

Closed via 0150367