Skydoc documentation

Overview

These rules were initially forked from pubref/rules_kotlin. Key changes:

• Replace the macros with three basic rules. kotlin_binary, kotlin_library and kotlin_test.
• Use a single dep attribute instead of java_dep and dep.
• Add support for the following standard java rules attributes:
  • data
  • resource_jars
  • runtime_deps
  • resources
  • resources_strip_prefix
  • exports
• Persistent worker support.
• Mixed-Mode compilation (compile Java and Kotlin in one pass).