apidoc is not be generated

[myunusov]

javadoc: error - No public or protected classes found to document.
:javadoc
1 error
:javadoc FAILED

FAILURE: Build failed with an exception.

• What went wrong:
  Execution failed for task ':javadoc'.

Javadoc generation failed. Generated Javadoc options file (useful for troubleshooting): 'D:\work\tutor\StartApp\build\tmp\javadoc\javadoc.options'

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

[myunusov]

see Kotlin/dokka#62