Fix the javadoc artifact having no content in releases

[mahozad]

The javadoc.jar artifact has no javadoc in it. For example, this javadoc for version 0.4.0 of the library.

See this post and this post and this page and also dokka homepage for setting up kdoc in Android.

Important

If the docs cannot be generated offline, add this block of code to the build script:

val dokka by tasks.getting(org.jetbrains.dokka.gradle.DokkaTask::class)
dokka.configure<org.jetbrains.dokka.gradle.DokkaTask> {
    dokkaSourceSets {
        named("main") {
            noAndroidSdkLink.set(false)
        }
    }
}

See this and this and Kotlin/dokka#1706 for more information about the noAndroidSdkLink property.