added table of contents to long description

setup.py

@@ -29,8 +29,7 @@ setup(name='zope.container',
       long_description=(
           read('README.txt')
           + '\n\n' +
-          'Detailed Documentation\n'
-          '**********************\n'
+          '.. contents::\n'
           + '\n\n' +
           read('src', 'zope', 'container', 'constraints.txt')
           + '\n\n' +

src/zope/container/constraints.txt

-Containment constraints
-=======================
+=========================
+ Containment constraints
+=========================
 
 Containment constraints allow us to express restrictions on the types
 of items that can be placed in containers or on the types of