fix doc list

Build/CMake/Modules/AtomicDocList.cmake

@@ -1,7 +1,7 @@
 # create target to generate docs with clang based doc tool
-# NB: pretty brute force ATM
-if(EXISTS "/usr/local/bin/cldoc")
-   add_custom_target(AtomicEngineDocs 
+find_program(CLDOC cldoc)
+if(CLDOC)
+   add_custom_target(AtomicEngineDocs
     DEPENDS AtomicEditorDocs AtomicDocs
     )
-endif()
+endif()