Copy the whole site source folder to the build dirctory

docs/site/CMakeLists.txt

-file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/static DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/versioned_docs DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/versioned_sidebars DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/src DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/plugins DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
-file(COPY ${CMAKE_CURRENT_SOURCE_DIR}/examples DESTINATION ${CMAKE_CURRENT_BINARY_DIR})
+file(COPY ${CMAKE_CURRENT_SOURCE_DIR} DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/..)
 
 add_custom_target(
         site ALL