fix doc list

Build/CMake/Modules/AtomicDocList.cmake

@@ -0,0 +1,7 @@
+# create target to generate docs with clang based doc tool
+find_program(CLDOC cldoc)
+if(CLDOC)
+   add_custom_target(AtomicEngineDocs
+    DEPENDS AtomicEditorDocs AtomicDocs
+    )
+endif()