Multiple keywords of KDoc Syntax are ignored for javadoc output format

[lkjh654]

There is no output generated for @param <name>, @return in the final javadoc.

1. checkout https://github.com/JetBrains/kotlin-examples/tree/master/gradle/dokka-gradle-example
2. modify source code to add @param <name>, @return keywords according to the documentation at https://kotlinlang.org/docs/reference/kotlin-doc.html
3. generate documentation using dokkaJavadoc command.

There is no output generated for the keywords, they simply seem to be ignored. The proper output is generated for html format.