Add section numbering to some of the larger subdocuments.
diff --git a/Doc/distutils/index.rst b/Doc/distutils/index.rst
index 6d82c84..ace8280 100644
--- a/Doc/distutils/index.rst
+++ b/Doc/distutils/index.rst
@@ -16,6 +16,7 @@
 
 .. toctree::
    :maxdepth: 2
+   :numbered:
 
    introduction.rst
    setupscript.rst