Provide code samples in Kotlin in addition to Java

Even if we have a dedicated Kotlin section in our reference documentation, all the code samples are in Java, requiring an effort for Kotlin users to translate it. I would like to make our documentation more natively Kotlin friendly by translating our code example to Kotlin.

This could be done via a Kotlin tab (in addition to the Java one) on each code sample block, and by generating 2 versions of the documentation: one in Java, one in Kotlin.