Add comment about updating docs

diff --git a/Tools/compiler/ast.txt b/Tools/compiler/ast.txt
index a235b99d6429b8e7b591cf4409cd9bce03ee080b..f2c0c999f5e106c4d061d00225dea93b756a2829 100644 (file)
--- a/Tools/compiler/ast.txt
+++ b/Tools/compiler/ast.txt
@@ -6,6 +6,9 @@
 #    !   this child is a sequence that contains nodes in it
 #    &   this child may be set to None
 #  = ... a default value for the node constructor (optional args)
+#
+# If you add node types here, please be sure to update the list of 
+# Node types in Doc/lib/asttable.tex.
 Module: doc*, node
 Stmt: nodes!
 Decorators: nodes!