Add to the documented stdlib files the theories used in examples.

Makefile.in

@@ -1265,6 +1265,7 @@ clean::
 
 STDLIBS = algebra \
 	bag \
+	bintree \
 	bool \
 	comparison \
 	floating_point \
@@ -1274,10 +1275,12 @@ STDLIBS = algebra \
 	map \
 	number \
 	option \
+	pigeon \
 	real \
 	relations \
-	set
-# function ? sum ? tptp ?
+	set \
+	sum
+# function ? tptp ?
 
 STDMODS = arith array hashtbl impset pqueue queue random ref stack string
 

theories/bintree.why

 
-(* Polymorphic binary trees with elements at nodes *)
+(** {1 Polymorphic binary trees with elements at nodes} *)
 
 theory Tree
 

theories/sum.why

 
+(** {1 Sum of the elements of an indexed container} *)
+
 theory Sum "Sum of the elements of an indexed container"
 
   use import int.Int