Fix forgot to reflect in the original text

Author: h-east

en/builtin.txt

@@ -6,9 +6,10 @@
 
 Builtin functions				*builtin-functions*
 
-Note: Expression evaluation can be disabled at compile time.  If this has been
-done, the builtin functions are not available.  See |+eval| and
-|no-eval-feature|.
+Note: Expression evaluation can be disabled at compile time, the builtin
+functions are not available then.  See |+eval| and |no-eval-feature|.
+
+For functions grouped by what they are used for see |function-list|.
 
 1. Overview				|builtin-function-list|
 2. Details				|builtin-function-details|