fix doc

src/types.ml

@@ -1,6 +1,7 @@
 (** Module defining types used to represent a config. *)
 
-(** A directive has a name, a list of parameters and a list of children. *)
+(** A directive has a name, a list of parameters and children (a list of
+    directive). *)
 type directive =
   { name : string
   ; params : string list