cmake doxygen_add_docs(CONFIG_FILE) examples

FreeRDP/FreeRDP cmake/Doxygen.cmake :15 

doxygen_add_docs(
  docs "${CMAKE_SOURCE_DIR}" ALL COMMENT "Generate doxygen docs"
  WORKING_DIRECTORY "${CMAKE_SOURCE_DIR}/docs" CONFIG_FILE "${CMAKE_SOURCE_DIR}/docs/Doxyfile"
)