add a warning about bgen being removed
diff --git a/Tools/README b/Tools/README
index 404ba4d..97b3823 100644
--- a/Tools/README
+++ b/Tools/README
@@ -9,6 +9,7 @@
 
 bgen		Generate complete extension modules from a
 		description.  Still under development!
+                WARNING: bgen has been removed in 3.0
 
 compiler	Tools used to maintain the compiler package in the
 		standard library.