Tweak doxygen settings: ignore the detail namespaces

cetlvast/suites/docs/doxygen.ini

@@ -1042,7 +1042,7 @@ EXCLUDE_PATTERNS       =
 # Note that the wildcards are matched against the file with absolute path, so to
 # exclude all test directories use the pattern */test/*
 
-EXCLUDE_SYMBOLS        =
+EXCLUDE_SYMBOLS        = *::impl::*,*::detail::*
 
 # The EXAMPLE_PATH tag can be used to specify one or more files or directories
 # that contain example code fragments that are included (see the \include